The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F INFORMATION TABLE
OMB APPROVAL
OMB Number: 3235-0006
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COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8
VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER VOTING AUTHORITY
NAME OF ISSUER TITLE OF CLASS CUSIP (x$1000) PRN AMT PRN CALL DISCRETION MANAGER SOLE SHARED NONE
ABB Ltd SPONSORED ADR 000375204 1 49 SH   SOLE   49 0 0
Acuity Brands, Inc. COM 00508Y102 2 15 SH   SOLE   15 0 0
Adient PLC ORD SHS G0084W101 0 6 SH   SOLE   6 0 0
Advanced Energy Industries, In COM 007973100 1 22 SH   SOLE   22 0 0
Albemarle Corporation COM 012653101 4 38 SH   SOLE   38 0 0
Algonquin Power & Utilities COM 015857105 1 114 SH   SOLE   114 0 0
American Water Works Company, COM 030420103 10 118 SH   SOLE   118 0 0
Anadarko Petroleum Corp COM 032511107 10,628 145,098 SH   SOLE   145,098 0 0
Andeavor COM 03349M105 2,122 16,173 SH   SOLE   16,173 0 0
Andeavor Logistics LP COM UNIT LP INT 03350F106 575,816 13,539,065 SH   SOLE   12,169,980 0 1,369,085
Antero Midstream GP LP COM SHS REPSTG 03675Y103 114,921 5,532,585 SH   SOLE   5,532,585 0 0
Antero Midstream Partners LP UNT LTD PARTN 03673L103 353,027 10,477,245 SH   SOLE   10,477,245 0 0
Antero Resources Corp COM 03674X106 8,452 395,867 SH   SOLE   395,867 0 0
Apache Corp COM 037411105 2 42 SH   SOLE   42 0 0
Aptiv PLC SHS G6095L109 2 18 SH   SOLE   18 0 0
Aqua America, Inc. COM 03836W103 1 30 SH   SOLE   30 0 0
Aquaventure Holdings Ltd SHS G0443N107 4 277 SH   SOLE   277 0 0
Atlantica Yield PLC SHS G0751N103 38 1,861 SH   SOLE   1,861 0 0
Autoliv Inc COM 052800109 1 8 SH   SOLE   8 0 0
Badger Meter, Inc. COM 056525108 2 53 SH   SOLE   53 0 0
Baker Hughes, a GE Company, LL CL A 05722G100 2 69 SH   SOLE   69 0 0
BorgWarner Inc COM 099724106 1 24 SH   SOLE   24 0 0
BP Midstream Partners LP UNIT LTD PTNR 0556EL109 148,285 7,064,549 SH   SOLE   6,229,098 0 835,451
Brookfield Renewable Energy Pa PARTNERSHIP UNIT G16258108 17 564 SH   SOLE   564 0 0
Buckeye Partners, L.P. UNIT LTD PARTN 118230101 364,489 9,253,223 SH   SOLE   9,253,223 0 0
Cabot Oil & Gas Corp. COM 127097103 20,198 848,674 SH   SOLE   848,674 0 0
Cactus Inc. CL A 127203107 1 19 SH   SOLE   19 0 0
Carrizo Oil & Gas Inc COM 144577103 3,893 139,780 SH   SOLE   139,780 0 0
Celanese Corporation COM SER A 150870103 2 16 SH   SOLE   16 0 0
Centennial Resource Developmen CL A 15136A102 9,255 512,451 SH   SOLE   512,451 0 0
Chart Industries, Inc. COM PAR $0.01 16115Q308 0 7 SH   SOLE   7 0 0
Cheniere Energy Inc. COM NEW 16411R208 417,146 6,398,923 SH   SOLE   6,147,188 0 251,735
Cheniere Energy Partners LP COM UNIT 16411Q101 552 15,360 SH   SOLE   15,360 0 0
Cheniere Energy Partners LP Ho COM REP LLC IN 16411W108 4,868 154,776 SH   SOLE   154,776 0 0
Chevron Corp COM 166764100 2 18 SH   SOLE   18 0 0
Cia Energetica de Minas Gerais SP ADR N-V PFD 204409601 20 10,800 SH   SOLE   10,800 0 0
Cimarex Energy Co COM 171798101 8,853 87,018 SH   SOLE   87,018 0 0
Cms Energy Corp Com COM 125896100 157 3,322 SH   SOLE   3,322 0 0
Concho Resources Inc COM 20605P101 15,637 113,022 SH   SOLE   113,022 0 0
Connecticut Water Service, Inc COM 207797101 1 16 SH   SOLE   16 0 0
ConocoPhillips COM 20825c104 2 28 SH   SOLE   28 0 0
Continental Resources Inc COM 212015101 19,007 293,492 SH   SOLE   293,492 0 0
Core Laboratories N.V. COM N22717107 1 10 SH   SOLE   10 0 0
Covanta Holding Corporation COM 22282E102 33 2,000 SH   SOLE   2,000 0 0
Covia Holding Corp COM 22305A103 1,254 67,569 SH   SOLE   67,569 0 0
Cypress Semiconductor Corporat COM 232806109 1 33 SH   SOLE   33 0 0
Danaher Corporation COM 235851102 5 54 SH   SOLE   54 0 0
DCP Midstream LP COM UT LTD PTN 23311P100 78,872 1,994,241 SH   SOLE   1,994,241 0 0
Delek US Holdings, Inc. COM 24665A103 1,728 34,448 SH   SOLE   34,448 0 0
Delphi Technologies PLC SHS G2709G107 1 24 SH   SOLE   24 0 0
Devon Energy Corporation COM 25179M103 17,973 408,853 SH   SOLE   408,853 0 0
Diamondback Energy Inc COM 25278X109 15,244 115,861 SH   SOLE   115,861 0 0
Dominion Energy Inc. COM 25746U109 221 3,237 SH   SOLE   3,237 0 0
Dominion Energy Midstream Part COM UT REP LTD 257454108 74,471 5,475,827 SH   SOLE   4,774,182 0 701,645
Dril-Quip, Inc. COM 262037104 1 20 SH   SOLE   20 0 0
DTE Energy Company COM 233331107 4 41 SH   SOLE   41 0 0
DTE Energy Preferred UNIT 99/99/9999 233331883 2,047 39,600 SH   SOLE   39,600 0 0
Duke Energy Corporation COM 26441C204 3 36 SH   SOLE   36 0 0
Eastman Chemical Co COM 277432100 2 17 SH   SOLE   17 0 0
Ecolab Inc. COM 278865100 4 32 SH   SOLE   32 0 0
Edison International COM 281020107 3 49 SH   SOLE   49 0 0
Enbridge Energy Management, LL SHS UNITS LLI 29250X103 21,816 2,126,290 SH   SOLE   2,126,290 0 0
Enbridge Energy Partners, L.P. COM 29250R106 103,201 9,442,022 SH   SOLE   9,442,022 0 0
Enbridge Inc COM 29250N105 241,178 6,757,583 SH   SOLE   6,757,583 0 0
Energy Recovery Inc COM 29270J100 1 72 SH   SOLE   72 0 0
Energy Transfer Equity, L.P. COM UT LTD PTN 29273V100 530,722 30,766,490 SH   SOLE   26,213,335 0 4,553,155
Energy Transfer Partners, L.P. UNIT LTD PRT INT 29278N103 799,542 41,992,731 SH   SOLE   38,530,904 0 3,461,827
Enlink Midstream Partners, LP COM UNIT REP LTD 29336U107 125,668 8,091,966 SH   SOLE   8,091,966 0 0
Enlink Midstream, LLC COM UNIT REP LTD 29336T100 81,601 4,960,576 SH   SOLE   4,960,576 0 0
Ensco PLC SHS CLASS A G3157S106 0 35 SH   SOLE   35 0 0
Enterprise Products Partners L COM 293792107 1,090,718 39,418,808 SH   SOLE   34,217,802 0 5,201,006
EOG Resources Inc COM 26875P101 25,039 201,228 SH   SOLE   201,228 0 0
EQT Corp COM 26884L109 17,610 319,143 SH   SOLE   319,143 0 0
EQT GP Holdings LP COM UNIT REP 26885J103 42,692 1,815,908 SH   SOLE   1,545,152 0 270,756
EQT Midstream Partners, LP UNIT LTD PARTN 26885B100 525,639 10,188,782 SH   SOLE   8,815,966 0 1,372,816
Esco Technologies Inc. COM 296315104 2 35 SH   SOLE   35 0 0
Evoqua Water Technologies Corp COM 30057T105 4 209 SH   SOLE   209 0 0
Extraction Oil & Gas, LLC COM 30227M105 5,105 347,496 SH   SOLE   347,496 0 0
Exxon Mobil Corp COM 30231G102 3 35 SH   SOLE   35 0 0
FireEye Inc COM 31816Q101 1 53 SH   SOLE   53 0 0
Ford Motor Co COM PAR $0.01 345370860 1 135 SH   SOLE   135 0 0
Forum Energy Technologies, Inc COM 34984V100 1 41 SH   SOLE   41 0 0
FTS International Inc. COM 30283W104 1 49 SH   SOLE   49 0 0
Genesis Energy L.P. UNIT LTD PARTN 371927104 1,020 46,539 SH   SOLE   46,539 0 0
Gentex Corporation COM 371901109 1 24 SH   SOLE   24 0 0
Golar LNG Ltd SHS G9456A100 1 25 SH   SOLE   25 0 0
Gulfport Energy Corp COM 402635304 1 53 SH   SOLE   53 0 0
Halcon Resources Corp - Restri COM PAR 40537Q605 4,258 970,000 SH   SOLE   970,000 0 0
Halliburton Company COM 406216101 1,950 43,265 SH   SOLE   43,265 0 0
Hannon Armstrong Sustainable I COM 41068X100 38 1,932 SH   SOLE   1,932 0 0
Helmerich & Payne, Inc. COM 423452101 1 20 SH   SOLE   20 0 0
Hess Corp COM 42809H107 1 13 SH   SOLE   13 0 0
Hess Corp DEP PDF SR A 42809H404 4,522 60,000 SH   SOLE   60,000 0 0
Holly Energy Partners, L.P. COM UT LTD PTN 435763107 188,005 6,652,705 SH   SOLE   6,652,705 0 0
HollyFrontier Corporation COM 436106108 2,674 39,077 SH   SOLE   39,077 0 0
Hortonworks Inc COM 440894103 1 50 SH   SOLE   50 0 0
IDEX Corporation COM 45167R104 4 29 SH   SOLE   29 0 0
InfraREIT Inc. COM 45685L100 24 1,080 SH   SOLE   1,080 0 0
Itron, Inc. COM 465741106 5 90 SH   SOLE   90 0 0
Keane Group Inc. COM 48669A108 1 47 SH   SOLE   47 0 0
Kinder Morgan Inc COM 49456B101 322,577 18,255,609 SH   SOLE   18,255,609 0 0
Laredo Petroleum, Inc. COM 516806106 3,393 352,676 SH   SOLE   352,676 0 0
Lear Corporation COM 521865204 1 3 SH   SOLE   3 0 0
Lindsay Corporation COM 535555106 1 6 SH   SOLE   6 0 0
Magellan Midstream Partners, L COM UNIT RP LP 559080106 1,036,271 15,001,029 SH   SOLE   13,018,684 0 1,982,345
Magna International Inc COM 559222401 3 44 SH   SOLE   44 0 0
Marathon Oil Corp COM 565849106 2 115 SH   SOLE   115 0 0
Marathon Petroleum Corp COM 56585A102 793 11,297 SH   SOLE   11,297 0 0
Micron Technology Inc COM 595112103 1 12 SH   SOLE   12 0 0
MiX Telematics Ltd SPONSORED ADR 60688N102 18 1,000 SH   SOLE   1,000 0 0
Monolithic Power Systems Inc COM 609839105 4 27 SH   SOLE   27 0 0
MPLX LP COM UNIT REP LTD 55336V100 918,984 26,918,106 SH   SOLE   23,439,143 0 3,478,963
MRC Global Inc. COM 55345K103 1 27 SH   SOLE   27 0 0
Mueller Water Products, Inc. COM SER A 624758108 3 257 SH   SOLE   257 0 0
National Fuel Gas Co COM 636180101 20,462 386,366 SH   SOLE   386,366 0 0
NATIONAL OILWELL VARCO INC COM COM 637071101 1 22 SH   SOLE   22 0 0
NCS Multistage Holdings Inc COM 628877102 0 21 SH   SOLE   21 0 0
Newfield Exploration Co COM 651290108 6,605 218,358 SH   SOLE   218,358 0 0
Newpark Resources, Inc. COM PAR $.01 651718504 1 91 SH   SOLE   91 0 0
Nextera Energy Inc COM 65339F101 377 2,257 SH   SOLE   2,257 0 0
Nextera Energy Partners LP COM UNIT PART IN 65341B106 381 8,168 SH   SOLE   8,168 0 0
Nisource Inc COM 65473P105 44,409 1,689,858 SH   SOLE   1,689,858 0 0
Noble Energy Inc COM 655044105 1,140 32,300 SH   SOLE   32,300 0 0
Noble Midstream Partners LP COM UNIT REPST 65506L105 113,615 2,225,122 SH   SOLE   1,996,260 0 228,862
NRG Yield, Inc. - Class C CL C 62942X405 25 1,451 SH   SOLE   1,451 0 0
NuStar Energy L.P. UNIT COM 67058H102 55,637 2,456,374 SH   SOLE   2,456,374 0 0
nVent Electric PLC SHS G6700G107 1 23 SH   SOLE   23 0 0
NVIDIA Corporation COM 67066G104 2 9 SH   SOLE   9 0 0
Occidental Petroleum Corp COM 674599105 3,493 41,740 SH   SOLE   41,740 0 0
Oceaneering International Inc. COM 675232102 1 27 SH   SOLE   27 0 0
Olin Corporation COM PAR $1 680665205 1 42 SH   SOLE   42 0 0
ONEOK, Inc COM 682680103 966,663 13,843,087 SH   SOLE   12,567,191 0 1,275,896
Ormat Technologies, Inc. COM 686688102 2 32 SH   SOLE   32 0 0
Parsley Energy, Inc. CL A 701877102 7,748 255,868 SH   SOLE   255,868 0 0
Pattern Energy Group Inc. CL A 70338P100 30 1,592 SH   SOLE   1,592 0 0
Patterson-UTI Energy, Inc. COM 703481101 1 64 SH   SOLE   64 0 0
PDC Energy Inc COM 69327R101 3,538 58,526 SH   SOLE   58,526 0 0
Pembina Pipeline Corp COM 706327103 203,334 5,871,153 SH   SOLE   5,871,153 0 0
Pentair plc SHS G7S00T104 5 129 SH   SOLE   129 0 0
Phillips 66 Partners LP COM UNIT REP INT 718549207 544,074 10,655,570 SH   SOLE   9,383,779 0 1,271,791
Pioneer Natural Resources Co COM 723787107 24,310 128,461 SH   SOLE   128,461 0 0
Plains All American Pipeline, UNIT LTD PARTN 726503105 706,235 29,874,584 SH   SOLE   25,773,026 0 4,101,558
Plains GP Holdings, L.P. LTD PARTNR INT A 72651A207 221,736 9,273,785 SH   SOLE   9,273,785 0 0
PPL Corporation COM 69351T106 3 96 SH   SOLE   96 0 0
QEP Resources Inc. COM 74733V100 1 68 SH   SOLE   68 0 0
Range Resources Corp COM 75281A109 9,102 544,060 SH   SOLE   544,060 0 0
Rice Midstream Partners LP UNIT LTD PARTN 762819100 112,193 6,591,850 SH   SOLE   6,591,850 0 0
RSP Permian, Inc. COM 74978Q105 790 17,950 SH   SOLE   17,950 0 0
Schlumberger, Ltd. COM 806857108 4 66 SH   SOLE   66 0 0
Semgroup Corp CL A 81663A105 93,515 3,681,697 SH   SOLE   3,681,697 0 0
Sempra Energy COM 816851109 244 2,101 SH   SOLE   2,101 0 0
Sempra Energy - Preferred Shar 6% PFD CONV A 816851406 5,161 50,000 SH   SOLE   50,000 0 0
Shell Midstream Partners LP UNIT LTD INT 822634101 392,108 17,678,457 SH   SOLE   16,023,879 0 1,654,578
SM Energy Co COM 78454L100 2,499 97,259 SH   SOLE   97,259 0 0
Spectra Energy Partners, LP COM 84756N109 88,005 2,484,607 SH   SOLE   2,484,607 0 0
Splunk Inc COM 848637104 1 10 SH   SOLE   10 0 0
Sunrun Inc COM 86771W105 4 294 SH   SOLE   294 0 0
Superior Energy Services, Inc. COM 868157108 1 74 SH   SOLE   74 0 0
Tallgrass Energy LP SHS CL A 874696107 119,824 5,407,201 SH   SOLE   5,094,676 0 312,525
Tallgrass Energy Partners, LP COM UNIT 874697105 387,057 8,936,892 SH   SOLE   8,006,210 0 930,682
Targa Resources Corp. COM 87612G101 416,422 8,414,256 SH   SOLE   7,784,355 0 629,901
TechnipFMC PLC COM G87110105 1 31 SH   SOLE   31 0 0
Terraform Power Inc COM CL A 88104R209 39 3,299 SH   SOLE   3,299 0 0
Tesla Inc. COM 88160R101 13 37 SH   SOLE   37 0 0
Tetra Tech, Inc. COM 88162G103 3 51 SH   SOLE   51 0 0
The Goodyear Tire & Rubber Com COM 382550101 1 31 SH   SOLE   31 0 0
Tortoise North American Pipeli TORTOISE NRAM PI 56167N720 180 7,745 SH   SOLE   7,745 0 0
Transcanada Corp COM 89353D107 337,782 7,819,029 SH   SOLE   7,819,029 0 0
U.S. Silica Holdings, Inc. COM 90346E103 3,009 117,135 SH   SOLE   117,135 0 0
USA Compression Partners LP COMUNIT LTDPAR 90290N109 1 33 SH   SOLE   33 0 0
Valero Energy Corp COM 91913Y100 3,714 33,507 SH   SOLE   33,507 0 0
Valero Energy Partners LP COM UNT REP LP 91914J102 249,159 6,544,766 SH   SOLE   5,699,212 0 845,554
Verisk Analytics Inc COM 92345Y106 1 5 SH   SOLE   5 0 0
Vistra Energy Corp. COM 92840M102 1 63 SH   SOLE   63 0 0
Watts Water Technologies, Inc. CL A 942749102 3 37 SH   SOLE   37 0 0
WEC Energy Group, Inc. COM 92939U106 232 3,584 SH   SOLE   3,584 0 0
Western Gas Equity Partners, L COMUNT LTD PT 95825R103 66,881 1,870,803 SH   SOLE   1,676,321 0 194,482
Western Gas Partners LP COM UNIT LP IN 958254104 724,022 14,962,223 SH   SOLE   13,222,948 0 1,739,275
Westlake Chem Corp Com COM 960413102 2,736 25,417 SH   SOLE   25,417 0 0
WildHorse Resource Development COM 96812T102 4,066 160,342 SH   SOLE   160,342 0 0
Williams Companies, Inc COM 969457100 456,087 16,823,579 SH   SOLE   16,089,718 0 733,861
Williams Partners L.P. COM UNIT LTD PAR 96949L105 802,075 19,760,408 SH   SOLE   16,835,917 0 2,924,491
WPX Energy Inc COM 98212B103 13,132 728,360 SH   SOLE   728,360 0 0
Xylem Inc. COM 98419M100 11 166 SH   SOLE   166 0 0