<informationTable xmlns="http://www.sec.gov/edgar/document/thirteenf/informationtable">		<infoTable>
			<nameOfIssuer>DLH HLDGS CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>23335Q100</cusip>
			<value>94</value>
			<shrsOrPrnAmt>
				<sshPrnamt>47999</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>OTR</investmentDiscretion>
			<votingAuthority>
				<Sole>47999</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ECHO THERAPEUTICS INC</nameOfIssuer>
			<titleOfClass>COM NEW</titleOfClass>
			<cusip>27876L906</cusip>
			<value>804</value>
			<shrsOrPrnAmt>
				<sshPrnamt>377633</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>OTR</investmentDiscretion>
			<votingAuthority>
				<Sole>377633</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>INSPIREMD INC</nameOfIssuer>
			<titleOfClass>COM NEW</titleOfClass>
			<cusip>45779A309</cusip>
			<value>8</value>
			<shrsOrPrnAmt>
				<sshPrnamt>24453</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>OTR</investmentDiscretion>
			<votingAuthority>
				<Sole>24453</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>NAVIDEA BIOPHARMACEUTICALS I</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>63937X103</cusip>
			<value>18213</value>
			<shrsOrPrnAmt>
				<sshPrnamt>11454831</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>OTR</investmentDiscretion>
			<votingAuthority>
				<Sole>11454831</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>NAVIDEA BIOPHARMACEUTICALS I</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>63937X103</cusip>
			<value>9699</value>
			<shrsOrPrnAmt>
				<sshPrnamt>6100000</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<putCall>Call</putCall>
			<investmentDiscretion>OTR</investmentDiscretion>
			<votingAuthority>
				<Sole>6100000</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>PEDEVCO CORP</nameOfIssuer>
			<titleOfClass>COM NEW</titleOfClass>
			<cusip>70532Y204</cusip>
			<value>28</value>
			<shrsOrPrnAmt>
				<sshPrnamt>34444</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>OTR</investmentDiscretion>
			<votingAuthority>
				<Sole>34444</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>VIRCO MFG CO</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>927651109</cusip>
			<value>185</value>
			<shrsOrPrnAmt>
				<sshPrnamt>68179</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>OTR</investmentDiscretion>
			<votingAuthority>
				<Sole>68179</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
</informationTable>
