<informationTable xmlns="http://www.sec.gov/edgar/document/thirteenf/informationtable">		<infoTable>
			<nameOfIssuer>AZZ INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>002474104</cusip>
			<value>12954</value>
			<shrsOrPrnAmt>
				<sshPrnamt>217722</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>1225</Sole>
				<Shared>190548</Shared>
				<None>25949</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>AMETEK INC NEW</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>031100100</cusip>
			<value>11276</value>
			<shrsOrPrnAmt>
				<sshPrnamt>208505</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>22519</Sole>
				<Shared>185986</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>AMPHENOL CORP NEW</nameOfIssuer>
			<titleOfClass>CL A</titleOfClass>
			<cusip>032095101</cusip>
			<value>22471</value>
			<shrsOrPrnAmt>
				<sshPrnamt>315730</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>32662</Sole>
				<Shared>283068</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ANALOG DEVICES INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>032654105</cusip>
			<value>2092</value>
			<shrsOrPrnAmt>
				<sshPrnamt>25531</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>2425</Sole>
				<Shared>23106</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ANALOGIC CORP</nameOfIssuer>
			<titleOfClass>COM PAR $0.05</titleOfClass>
			<cusip>032657207</cusip>
			<value>18994</value>
			<shrsOrPrnAmt>
				<sshPrnamt>250247</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>1347</Sole>
				<Shared>218245</Shared>
				<None>30655</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>AUTOZONE INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>053332102</cusip>
			<value>3866</value>
			<shrsOrPrnAmt>
				<sshPrnamt>5347</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>506</Sole>
				<Shared>4841</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>BWX TECHNOLOGIES INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>05605H100</cusip>
			<value>13843</value>
			<shrsOrPrnAmt>
				<sshPrnamt>290825</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>30764</Sole>
				<Shared>260061</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>BIO TECHNE CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>09073M104</cusip>
			<value>2260</value>
			<shrsOrPrnAmt>
				<sshPrnamt>22232</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>2345</Sole>
				<Shared>19887</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CABOT CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>127055101</cusip>
			<value>37152</value>
			<shrsOrPrnAmt>
				<sshPrnamt>620137</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>14728</Sole>
				<Shared>542939</Shared>
				<None>62470</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CABOT MICROELECTRONICS CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>12709P103</cusip>
			<value>23333</value>
			<shrsOrPrnAmt>
				<sshPrnamt>304575</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>1704</Sole>
				<Shared>264267</Shared>
				<None>38604</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CARDTRONICS PLC</nameOfIssuer>
			<titleOfClass>SHS CL A</titleOfClass>
			<cusip>G1991C105</cusip>
			<value>55306</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1183006</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>26438</Sole>
				<Shared>1033027</Shared>
				<None>123541</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CHEMICAL FINL CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>163731102</cusip>
			<value>27125</value>
			<shrsOrPrnAmt>
				<sshPrnamt>530303</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>24265</Sole>
				<Shared>466179</Shared>
				<None>39859</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CLEAN HARBORS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>184496107</cusip>
			<value>68523</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1231985</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>42602</Sole>
				<Shared>1079552</Shared>
				<None>109831</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>COACH INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>189754104</cusip>
			<value>1540</value>
			<shrsOrPrnAmt>
				<sshPrnamt>37265</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>3517</Sole>
				<Shared>33748</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>COGNEX CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>192422103</cusip>
			<value>37374</value>
			<shrsOrPrnAmt>
				<sshPrnamt>445190</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>2550</Sole>
				<Shared>387061</Shared>
				<None>55579</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>COPART INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>217204106</cusip>
			<value>99301</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1603443</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>44140</Sole>
				<Shared>1401667</Shared>
				<None>157636</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CORE LABORATORIES N V</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>N22717107</cusip>
			<value>4076</value>
			<shrsOrPrnAmt>
				<sshPrnamt>35283</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>3730</Sole>
				<Shared>31553</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>COVANTA HLDG CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>22282E102</cusip>
			<value>33842</value>
			<shrsOrPrnAmt>
				<sshPrnamt>2155550</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>35793</Sole>
				<Shared>1876654</Shared>
				<None>243103</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>DOLLAR TREE INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>256746108</cusip>
			<value>15510</value>
			<shrsOrPrnAmt>
				<sshPrnamt>197683</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>20367</Sole>
				<Shared>177316</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>DORMAN PRODUCTS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>258278100</cusip>
			<value>35453</value>
			<shrsOrPrnAmt>
				<sshPrnamt>431672</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>2418</Sole>
				<Shared>374460</Shared>
				<None>54794</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>EOG RES INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>26875P101</cusip>
			<value>2386</value>
			<shrsOrPrnAmt>
				<sshPrnamt>24457</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>2323</Sole>
				<Shared>22134</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>EMERGENT BIOSOLUTIONS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>29089Q105</cusip>
			<value>32941</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1134332</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>14409</Sole>
				<Shared>987170</Shared>
				<None>132753</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ENTEGRIS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>29362U104</cusip>
			<value>79490</value>
			<shrsOrPrnAmt>
				<sshPrnamt>3397019</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>104045</Sole>
				<Shared>2976901</Shared>
				<None>316073</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ESTERLINE TECHNOLOGIES CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>297425100</cusip>
			<value>36580</value>
			<shrsOrPrnAmt>
				<sshPrnamt>425098</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>2524</Sole>
				<Shared>390882</Shared>
				<None>31692</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>FCB FINL HLDGS INC</nameOfIssuer>
			<titleOfClass>CL A</titleOfClass>
			<cusip>30255G103</cusip>
			<value>22951</value>
			<shrsOrPrnAmt>
				<sshPrnamt>463190</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>2594</Sole>
				<Shared>402361</Shared>
				<None>58235</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>F M C CORP</nameOfIssuer>
			<titleOfClass>COM NEW</titleOfClass>
			<cusip>302491303</cusip>
			<value>12388</value>
			<shrsOrPrnAmt>
				<sshPrnamt>178012</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>18574</Sole>
				<Shared>159438</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>GENESCO INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>371532102</cusip>
			<value>12261</value>
			<shrsOrPrnAmt>
				<sshPrnamt>221113</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>1224</Sole>
				<Shared>192586</Shared>
				<None>27303</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>GENESEE &amp; WYO INC</nameOfIssuer>
			<titleOfClass>CL A</titleOfClass>
			<cusip>371559105</cusip>
			<value>10062</value>
			<shrsOrPrnAmt>
				<sshPrnamt>148274</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>15354</Sole>
				<Shared>132920</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>GRACO INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>384109104</cusip>
			<value>56765</value>
			<shrsOrPrnAmt>
				<sshPrnamt>602986</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>12511</Sole>
				<Shared>525530</Shared>
				<None>64945</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>HALOZYME THERAPEUTICS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>40637H109</cusip>
			<value>30047</value>
			<shrsOrPrnAmt>
				<sshPrnamt>2318433</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>58292</Sole>
				<Shared>2025246</Shared>
				<None>234895</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>HEICO CORP NEW</nameOfIssuer>
			<titleOfClass>CL A</titleOfClass>
			<cusip>422806208</cusip>
			<value>82461</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1099484</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>23251</Sole>
				<Shared>1008998</Shared>
				<None>67235</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>HELEN OF TROY CORP LTD</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>G4388N106</cusip>
			<value>49075</value>
			<shrsOrPrnAmt>
				<sshPrnamt>520961</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>13598</Sole>
				<Shared>454898</Shared>
				<None>52465</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SCHEIN HENRY INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>806407102</cusip>
			<value>11673</value>
			<shrsOrPrnAmt>
				<sshPrnamt>68677</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>7349</Sole>
				<Shared>61328</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>IDEX CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>45167R104</cusip>
			<value>74557</value>
			<shrsOrPrnAmt>
				<sshPrnamt>797313</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>17573</Sole>
				<Shared>695884</Shared>
				<None>83856</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>INGREDION INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>457187102</cusip>
			<value>82784</value>
			<shrsOrPrnAmt>
				<sshPrnamt>687402</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>21643</Sole>
				<Shared>601836</Shared>
				<None>63923</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>KEYW HLDG CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>493723100</cusip>
			<value>14150</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1498969</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>8394</Sole>
				<Shared>1300621</Shared>
				<None>189954</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>KAMAN CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>483548103</cusip>
			<value>25871</value>
			<shrsOrPrnAmt>
				<sshPrnamt>537526</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>3187</Sole>
				<Shared>494297</Shared>
				<None>40042</None>
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			<nameOfIssuer>KAR AUCTION SVCS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>48238T109</cusip>
			<value>90758</value>
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				<sshPrnamt>2078278</sshPrnamt>
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			<investmentDiscretion>DFND</investmentDiscretion>
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				<Sole>57954</Sole>
				<Shared>1817682</Shared>
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		<infoTable>
			<nameOfIssuer>KIRBY CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>497266106</cusip>
			<value>4339</value>
			<shrsOrPrnAmt>
				<sshPrnamt>61500</sshPrnamt>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>6521</Sole>
				<Shared>54979</Shared>
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		<infoTable>
			<nameOfIssuer>LKQ CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>501889208</cusip>
			<value>8315</value>
			<shrsOrPrnAmt>
				<sshPrnamt>284069</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>29918</Sole>
				<Shared>254151</Shared>
				<None>0</None>
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		<infoTable>
			<nameOfIssuer>LEGACY TEX FINL GROUP INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>52471Y106</cusip>
			<value>27471</value>
			<shrsOrPrnAmt>
				<sshPrnamt>688487</sshPrnamt>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>3799</Sole>
				<Shared>595704</Shared>
				<None>88984</None>
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		<infoTable>
			<nameOfIssuer>MARKEL CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>570535104</cusip>
			<value>14047</value>
			<shrsOrPrnAmt>
				<sshPrnamt>14394</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>1477</Sole>
				<Shared>12917</Shared>
				<None>0</None>
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		<infoTable>
			<nameOfIssuer>MASTERCARD INC</nameOfIssuer>
			<titleOfClass>CL A</titleOfClass>
			<cusip>57636Q104</cusip>
			<value>4518</value>
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				<sshPrnamt>40169</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>3798</Sole>
				<Shared>36371</Shared>
				<None>0</None>
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		<infoTable>
			<nameOfIssuer>MEDTRONIC PLC</nameOfIssuer>
			<titleOfClass>SHS</titleOfClass>
			<cusip>G5960L103</cusip>
			<value>3888</value>
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				<sshPrnamt>48260</sshPrnamt>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>4585</Sole>
				<Shared>43675</Shared>
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		<infoTable>
			<nameOfIssuer>MID-AMER APT CMNTYS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>59522J103</cusip>
			<value>37050</value>
			<shrsOrPrnAmt>
				<sshPrnamt>364163</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>15633</Sole>
				<Shared>319656</Shared>
				<None>28874</None>
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		<infoTable>
			<nameOfIssuer>MINERALS TECHNOLOGIES INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>603158106</cusip>
			<value>15783</value>
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				<sshPrnamt>206046</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>1112</Sole>
				<Shared>179725</Shared>
				<None>25209</None>
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		<infoTable>
			<nameOfIssuer>OMNICELL INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>68213N109</cusip>
			<value>10993</value>
			<shrsOrPrnAmt>
				<sshPrnamt>270440</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>1728</Sole>
				<Shared>233791</Shared>
				<None>34921</None>
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		<infoTable>
			<nameOfIssuer>PDF SOLUTIONS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>693282105</cusip>
			<value>24574</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1086382</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>6101</Sole>
				<Shared>943729</Shared>
				<None>136552</None>
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		<infoTable>
			<nameOfIssuer>POWER INTEGRATIONS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>739276103</cusip>
			<value>34739</value>
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				<sshPrnamt>528346</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>2904</Sole>
				<Shared>460326</Shared>
				<None>65116</None>
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		<infoTable>
			<nameOfIssuer>RBC BEARINGS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>75524B104</cusip>
			<value>64039</value>
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				<sshPrnamt>659586</sshPrnamt>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>3672</Sole>
				<Shared>569625</Shared>
				<None>86289</None>
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		<infoTable>
			<nameOfIssuer>RLI CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>749607107</cusip>
			<value>27268</value>
			<shrsOrPrnAmt>
				<sshPrnamt>454314</sshPrnamt>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>2539</Sole>
				<Shared>394255</Shared>
				<None>57520</None>
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		<infoTable>
			<nameOfIssuer>ROCKWELL COLLINS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>774341101</cusip>
			<value>11758</value>
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				<sshPrnamt>121014</sshPrnamt>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>12516</Sole>
				<Shared>108498</Shared>
				<None>0</None>
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		<infoTable>
			<nameOfIssuer>SRC ENERGY INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>78470V108</cusip>
			<value>4136</value>
			<shrsOrPrnAmt>
				<sshPrnamt>490077</sshPrnamt>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>2743</Sole>
				<Shared>424920</Shared>
				<None>62414</None>
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		<infoTable>
			<nameOfIssuer>SENSIENT TECHNOLOGIES CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>81725T100</cusip>
			<value>25003</value>
			<shrsOrPrnAmt>
				<sshPrnamt>315450</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>1776</Sole>
				<Shared>274711</Shared>
				<None>38963</None>
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		<infoTable>
			<nameOfIssuer>SERVICEMASTER GLOBAL HLDGS I</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>81761R109</cusip>
			<value>6957</value>
			<shrsOrPrnAmt>
				<sshPrnamt>166626</sshPrnamt>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>17403</Sole>
				<Shared>149223</Shared>
				<None>0</None>
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		<infoTable>
			<nameOfIssuer>SIMPSON MANUFACTURING CO INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>829073105</cusip>
			<value>36275</value>
			<shrsOrPrnAmt>
				<sshPrnamt>841841</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>4765</Sole>
				<Shared>735474</Shared>
				<None>101602</None>
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		<infoTable>
			<nameOfIssuer>STERIS PLC</nameOfIssuer>
			<titleOfClass>SHS USD</titleOfClass>
			<cusip>G84720104</cusip>
			<value>7138</value>
			<shrsOrPrnAmt>
				<sshPrnamt>102767</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>10687</Sole>
				<Shared>92080</Shared>
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		<infoTable>
			<nameOfIssuer>SYNOPSYS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>871607107</cusip>
			<value>9932</value>
			<shrsOrPrnAmt>
				<sshPrnamt>137692</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>14612</Sole>
				<Shared>123080</Shared>
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		<infoTable>
			<nameOfIssuer>TD AMERITRADE HLDG CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>87236Y108</cusip>
			<value>8532</value>
			<shrsOrPrnAmt>
				<sshPrnamt>219561</sshPrnamt>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>23413</Sole>
				<Shared>196148</Shared>
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		<infoTable>
			<nameOfIssuer>TELEDYNE TECHNOLOGIES INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>879360105</cusip>
			<value>40696</value>
			<shrsOrPrnAmt>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>1720</Sole>
				<Shared>281325</Shared>
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			<nameOfIssuer>THERMON GROUP HLDGS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>88362T103</cusip>
			<value>13502</value>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
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			<nameOfIssuer>UGI CORP NEW</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>902681105</cusip>
			<value>73560</value>
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				<sshPrnamt>1489077</sshPrnamt>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>31284</Sole>
				<Shared>1302496</Shared>
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		<infoTable>
			<nameOfIssuer>UNITED CMNTY BKS BLAIRSVLE G</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>90984P303</cusip>
			<value>17183</value>
			<shrsOrPrnAmt>
				<sshPrnamt>620558</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>3471</Sole>
				<Shared>538296</Shared>
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			<nameOfIssuer>VALMONT INDS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>920253101</cusip>
			<value>3366</value>
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				<sshPrnamt>21647</sshPrnamt>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>2196</Sole>
				<Shared>19451</Shared>
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			<nameOfIssuer>VISA INC</nameOfIssuer>
			<titleOfClass>COM CL A</titleOfClass>
			<cusip>92826C839</cusip>
			<value>3909</value>
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				<sshPrnamt>43985</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>4162</Sole>
				<Shared>39823</Shared>
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		<infoTable>
			<nameOfIssuer>WASTE CONNECTIONS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>94106B101</cusip>
			<value>43167</value>
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			<investmentDiscretion>DFND</investmentDiscretion>
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				<Shared>432442</Shared>
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			<nameOfIssuer>WATERS CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>941848103</cusip>
			<value>3797</value>
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			<investmentDiscretion>DFND</investmentDiscretion>
			<votingAuthority>
				<Sole>2300</Sole>
				<Shared>21992</Shared>
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			<titleOfClass>COM</titleOfClass>
			<cusip>980745103</cusip>
			<value>56784</value>
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				<sshPrnamt>836047</sshPrnamt>
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			<investmentDiscretion>DFND</investmentDiscretion>
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				<Sole>21176</Sole>
				<Shared>764668</Shared>
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</informationTable>
