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
8point3 Energy Partners LP CL A RPT LTDPT 282539105 13 1,049 SH   SOLE   1,049 0 0
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, Inc. 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, Inc. COM 030420103 10 118 SH   SOLE   118 0 0
Anadarko Petroleum Corp COM 032511107 6 153,598 SH   SOLE   153,598 0 0
Anadarko Petroleum Corp UNIT 99/99/9999 032511404 20,654 693,100 SH   SOLE   693,100 0 0
Andeavor COM 03349M105 3,379 33,602 SH   SOLE   33,602 0 0
Andeavor Logistics LP COM UNIT LP INT 03350F106 587,996 13,121,984 SH   SOLE   11,575,319 0 1,546,665
Antero Midstream GP LP COM SHS REPSTG 03675Y103 89,047 5,568,945 SH   SOLE   4,996,277 0 572,668
Antero Midstream Partners LP UNT LTD PARTN 03673L103 292,724 11,306,444 SH   SOLE   9,778,601 0 1,527,843
Antero Resources Corp COM 03674X106 8,473 426,849 SH   SOLE   426,849 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 3 228 SH   SOLE   228 0 0
Atlantica Yield PLC SHS G0751N103 36 1,861 SH   SOLE   1,861 0 0
Autoliv Inc COM 052800109 1 8 SH   SOLE   8 0 0
Autoweb Inc COM 05335B100 0 163 SH   SOLE   163 0 0
Badger Meter, Inc. COM 056525108 2 53 SH   SOLE   53 0 0
Baker Hughes, a GE Company, LLC 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 124,647 6,986,964 SH   SOLE   6,170,793 0 816,171
Brookfield Renewable Energy Partners LP PARTNERSHIP UNIT G16258108 18 564 SH   SOLE   564 0 0
Buckeye Partners, L.P. UNIT LTD PARTN 118230101 402,177 10,844,679 SH   SOLE   9,687,243 0 1,157,436
Cabot Oil & Gas Corp. COM 127097103 19,267 803,446 SH   SOLE   803,446 0 0
Cactus Inc. CL A 127203107 1 19 SH   SOLE   19 0 0
Carrizo Oil & Gas Inc COM 144577103 3,158 197,380 SH   SOLE   197,380 0 0
Celanese Corporation COM SER A 150870103 2 16 SH   SOLE   16 0 0
Centennial Resource Development, Inc. CL A 15136A102 16,266 886,438 SH   SOLE   886,438 0 0
Chart Industries, Inc. COM PAR $0.01 16115Q308 0 7 SH   SOLE   7 0 0
Cheniere Energy Inc. COM NEW 16411R208 320,392 5,994,240 SH   SOLE   5,815,443 0 178,797
Cheniere Energy Partners LP COM UNIT 16411Q101 1 36 SH   SOLE   36 0 0
Cheniere Energy Partners LP Holdings, LLC COM REP LLC IN 16411W108 4,273 154,776 SH   SOLE   154,776 0 0
Chevron Corp COM 166764100 2 18 SH   SOLE   18 0 0
Cimarex Energy Co COM 171798101 9,445 101,018 SH   SOLE   101,018 0 0
Cms Energy Corp Com COM 125896100 150 3,322 SH   SOLE   3,322 0 0
Concho Resources Inc COM 20605P101 17,349 115,403 SH   SOLE   115,403 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 17,211 291,962 SH   SOLE   291,962 0 0
CNX Midstream Partners LP COM UNIT REPST 12654A101 1 10 SH   SOLE   10 0 0
Covanta Holding Corporation COM 22282E102 29 2,000 SH   SOLE   2,000 0 0
Cypress Semiconductor Corporation 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 80,354 2,287,978 SH   SOLE   2,287,978 0 0
Delphi Technologies PLC SHS G2709G107 1 24 SH   SOLE   24 0 0
Devon Energy Corporation COM 25179M103 540 293,199 SH   SOLE   293,199 0 0
Diamondback Energy Inc COM 25278X109 947 137,556 SH   SOLE   137,556 0 0
Dominion Energy Inc. COM 25746U109 4 2,764 SH   SOLE   2,764 0 0
Dominion Energy Midstream Partners LP COM UT REP LTD 257454108 83,796 5,459,048 SH   SOLE   5,351,298 0 107,750
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 2,063 39,600 SH   SOLE   39,600 0 0
Duke Energy Corporation COM NEW 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 Partners, L.P. COM 29250R106 18,740 49 SH   SOLE   2,050,343 0 0
Enbridge Energy Management, LLC SHS UNITS LLI 29250X103 95,710 9,928,428 SH   SOLE   9,928,428 0 0
Enbridge Inc COM 29250N105 172,008 5,465,786 SH   SOLE   2,050,343 0 0
Energy Recovery Inc COM 29270J100 1 72 SH   SOLE   5,465,786 0 0
Energy Transfer Equity, L.P. COM UT LTD PTN 29273V100 454,583 31,990,375 SH   SOLE   72 0 5,249,281
Energy Transfer Partners, L.P. UNIT LTD PTRT INT 29278N103 641,091 39,524,695 SH   SOLE   26,741,094 0 3,276,372
Enlink Midstream Partners, LP COM UNIT REP LTD 29336U107 110,536 8,091,952 SH   SOLE   36,248,323 0 0
Enlink Midstream, LLC COM UNIT REP LTD 29336T100 63,407 4,328,126 SH   SOLE   8,091,952 0 0
Ensco PLC SHS CLASS A G3157S106 0 35 SH   SOLE   4,328,126 0 0
Enterprise Products Partners L.P. COM 293792107 967,308 39,514,231 SH   SOLE   35 0 5,505,506
EOG Resources Inc COM 26875P101 24,760 235,204 SH   SOLE   34,008,725 0 0
EQT Corp COM 26884L109 12,296 258,817 SH   SOLE   235,204 0 0
EQT GP Holdings LP COM UNIT REP 26885J103 39,432 1,708,475 SH   SOLE   258,817 0 283,235
EQT Midstream Partners, LP UNIT LTD PARTN 26885B100 489,073 8,285,164 SH   SOLE   1,425,240 0 1,224,301
Esco Technologies Inc. COM 296315104 2 35 SH   SOLE   7,060,863 0 0
Evoqua Water Technologies Corp COM 30057T105 4 173 SH   SOLE   35 0 0
Extraction Oil & Gas, LLC COM 30227M105 3,982 347,496 SH   SOLE   173 0 0
Exxon Mobil Corp COM 30231G102 3 35 SH   SOLE   347,496 0 0
Fairmount Santrol Holdings Inc. COM 30555Q108 1,985 467,045 SH   SOLE   35 0 0
FireEye Inc COM 31816Q101 1 70 SH   SOLE   467,045 0 0
Ford Motor Co COM PAR $0.01 345370860 1 135 SH   SOLE   70 0 0
Forum Energy Technologies, Inc. COM 34984V100 0 41 SH   SOLE   135 0 0
FTS International Inc. COM 30283W104 895 48,658 SH   SOLE   41 0 0
Genesis Energy L.P. UNIT LTD PARTN 371927104 19 47,510 SH   SOLE   48,658 0 0
Gentex Corporation COM 371901109 1 24 SH   SOLE   47,510 0 0
Golar LNG Ltd SHS G9456A100 1 25 SH   SOLE   24 0 0
Gulfport Energy Corp COM NEW 402635304 1 53 SH   SOLE   25 0 0
Halcon Resources Corp - Restricted COM PAR NEW 40537Q605 4,724 970,000 SH   SOLE   53 0 0
Halliburton Company COM 406216101 651 54,883 SH   SOLE   970,000 0 0
Hannon Armstrong Sustainable Infrastructure Capital COM 41068X100 38 1,932 SH   SOLE   54,883 0 0
Helmerich & Payne, Inc. COM 423452101 1 20 SH   SOLE   1,932 0 0
Hess Corp COM 42809H107 1 13 SH   SOLE   20 0 0
Hess Corp DEP PDF SR A 42809H404 3,574 60,000 SH   SOLE   13 0 0
Holly Energy Partners, L.P. COM UT LTD PTN 435763107 1,177,648 6,579,080 SH   SOLE   60,000 0 0
HollyFrontier Corporation COM 436106108 1,887 38,625 SH   SOLE   6,579,080 0 0
Hortonworks Inc COM 440894103 0 50 SH   SOLE   38,625 0 0
IDEX Corporation COM 45167R104 4 29 SH   SOLE   0 0 0
InfraREIT Inc. COM 45685L100 21 1,080 SH   SOLE   29 0 0
Itron, Inc. COM 465741106 6 90 SH   SOLE   1,080 0 0
Keane Group Inc. COM 48669A108 868 58,651 SH   SOLE   90 0 0
Kinder Morgan Inc COM 49456B101 242,007 16,069,555 SH   SOLE   58,651 0 0
Laredo Petroleum, Inc. COM 516806106 3,356 385,276 SH   SOLE   16,069,555 0 0
Lear Corporation COM NEW 521865204 1 3 SH   SOLE   385,276 0 0
Lindsay Corporation COM 535555106 1 6 SH   SOLE   3 0 0
Magellan Midstream Partners, L.P. COM UNIT RP LP 559080106 854,724 14,648,222 SH   SOLE   6 0 2,049,292
Magna International Inc COM 559222401 2 44 SH   SOLE   12,598,930 0 0
Marathon Oil Corp COM 565849106 2 115 SH   SOLE   44 0 0
Marathon Petroleum Corp COM 56585A102 2,825 38,641 SH   SOLE   115 0 0
Micron Technology Inc COM 595112103 1 12 SH   SOLE   38,641 0 0
MiX Telematics Ltd SPONSORED ADR 60688N102 16 1,000 SH   SOLE   12 0 0
Monolithic Power Systems Inc COM 609839105 3 27 SH   SOLE   1,000 0 0
MPLX LP COM UNIT REP LTD 55336V100 831,048 25,152,777 SH   SOLE   27 0 3,286,634
MRC Global Inc. COM 55345K103 0 27 SH   SOLE   21,866,143 0 0
Mueller Water Products, Inc. COM SER A 624758108 3 257 SH   SOLE   27 0 0
National Fuel Gas Co COM 636180101 18,241 354,544 SH   SOLE   257 0 0
NATIONAL OILWELL VARCO INC COM 637071101 1 22 SH   SOLE   354,544 0 0
NCS Multistage Holdings Inc COM 628877102 0 21 SH   SOLE   22 0 0
Newfield Exploration Co COM 651290108 5,586 228,758 SH   SOLE   21 0 0
Newpark Resources, Inc. COM PAR $.01 NEW 651718504 1 91 SH   SOLE   228,758 0 0
Nextera Energy Inc COM 65339F101 330 2,020 SH   SOLE   91 0 0
Nextera Energy Partners LP COM UNIT PART IN 65341B106 305 7,631 SH   SOLE   2,020 0 0
Nisource Inc COM 65473P105 38,123 1,594,419 SH   SOLE   7,631 0 0
Noble Energy Inc COM 655044105 1,094 36,100 SH   SOLE   1,594,419 0 0
Noble Midstream Partners LP COM UNIT REPST 65506L105 101,075 2,167,957 SH   SOLE   36,100 0 240,232
NRG Yield, Inc. CL C 62942X405 25 1,451 SH   SOLE   1,927,725 0 0
NuStar Energy L.P. UNIT COM 67058H102 50,086 2,456,381 SH   SOLE   1,451 0 0
NVIDIA Corporation COM 67066G104 2 9 SH   SOLE   2,456,381 0 0
Occidental Petroleum Corp COM 674599105 2 24 SH   SOLE   9 0 0
Oceaneering International Inc. COM 675232102 1 27 SH   SOLE   24 0 0
Olin Corporation COM PAR $1 680665205 1 42 SH   SOLE   27 0 0
ONEOK, Inc COM 682680103 795,395 13,973,914 SH   SOLE   42 0 1,346,989
Ormat Technologies, Inc. COM 686688102 2 32 SH   SOLE   12,626,925 0 0
Parsley Energy, Inc. CL A 701877102 7,847 270,668 SH   SOLE   32 0 0
Pattern Energy Group Inc. CL A 70338P100 28 1,592 SH   SOLE   270,668 0 0
Patterson-UTI Energy, Inc. COM 703481101 1 64 SH   SOLE   1,592 0 0
PDC Energy Inc COM 69327R101 2,992 61,026 SH   SOLE   64 0 0
Pentair plc SHS G7S00T104 8 111 SH   SOLE   61,026 0 0
Phillips 66 COM 718546104 1,123 11,711 SH   SOLE   111 0 0
Phillips 66 Partners LP COM UNIT REP INT 718549207 465,152 9,735,232 SH   SOLE   11,711 0 1,171,854
Pioneer Natural Resources Co COM 723787107 24,350 141,752 SH   SOLE   8,563,378 0 0
Plains All American Pipeline, L.P. UNIT LTD PARTN 726503105 634,356 28,795,095 SH   SOLE   141,752 0 4,206,024
Plains GP Holdings, L.P. LTD PARTNR INT A 72651A207 189,542 8,714,594 SH   SOLE   24,589,071 0 0
PPL Corporation COM 69351T106 3 96 SH   SOLE   8,714,594 0 0
ProPetro Holding Corp COM 74347M108 1,340 84,327 SH   SOLE   96 0 0
QEP Resources Inc. COM 74733V100 1 68 SH   SOLE   84,327 0 0
Range Resources Corp COM 75281A109 7,915 544,360 SH   SOLE   68 0 0
Rice Midstream Partners LP UNIT LTD PARTN 762819100 113,830 6,288,973 SH   SOLE   544,360 0 0
RSP Permian, Inc. COM 74978Q105 15,003 320,032 SH   SOLE   6,288,973 0 0
Schlumberger, Ltd. COM 806857108 4 66 SH   SOLE   320,032 0 0
Semgroup Corp CL A 81663A105 68,702 3,210,388 SH   SOLE   66 0 0
Sempra Energy COM 816851109 234 2,101 SH   SOLE   3,210,388 0 0
Shell Midstream Partners LP UNIT LTD INT 822634101 346,770 16,473,649 SH   SOLE   2,101 0 2,132,160
SM Energy Co COM 78454L100 2,213 122,759 SH   SOLE   14,341,489 0 0
Spectra Energy Partners, LP COM 84756N109 175,330 5,211,945 SH   SOLE   122,759 0 638,837
Splunk Inc COM 848637104 1 12 SH   SOLE   4,573,108 0 0
Sunrun Inc COM 86771W105 3 294 SH   SOLE   12 0 0
Superior Energy Services, Inc. COM 868157108 1 74 SH   SOLE   294 0 0
Symantec Corp COM 871503108 1 35 SH   SOLE   74 0 0
Tallgrass Energy GP, LP SHS CL A 874696107 74,785 3,931,911 SH   SOLE   35 0 312,768
Tallgrass Energy Partners, LP COM UNIT 874697105 298,373 7,874,709 SH   SOLE   3,619,143 0 0
Targa Resources Corp. COM 87612G101 346,064 7,865,095 SH   SOLE   7,874,709 0 655,218
TC PipeLines, LP UT COM LTD PRT 87233Q108 1 16 SH   SOLE   7,209,877 0 0
TechnipFMC PLC COM G87110105 1 31 SH   SOLE   16 0 0
Terraform Power Inc COM CL A 88104R209 28 2,599 SH   SOLE   31 0 0
Tesla Inc. COM 88160R101 10 37 SH   SOLE   2,599 0 0
Tetra Tech, Inc. COM 88162G103 2 51 SH   SOLE   37 0 0
The Goodyear Tire & Rubber Company COM 382550101 1 31 SH   SOLE   51 0 0
Transcanada Corp COM 89353D107 290,871 7,041,174 SH   SOLE   31 0 0
U.S. Silica Holdings, Inc. COM 90346E103 4,642 181,880 SH   SOLE   7,041,174 0 0
USA Compression Partners LP COMUNIT LTDPAR 90290N109 1 33 SH   SOLE   181,880 0 0
Valero Energy Corp COM 91913Y100 2 26 SH   SOLE   33 0 0
Valero Energy Partners LP COM UNT REP LP 91914J102 214,248 6,047,076 SH   SOLE   26 0 822,533
Verisk Analytics Inc COM 92345Y106 1 5 SH   SOLE   5,224,543 0 0
Vistra Energy Corp. COM 92840M102 1 63 SH   SOLE   5 0 0
Watts Water Technologies, Inc. CL A 942749102 3 37 SH   SOLE   63 0 0
WEC Energy Group, Inc. COM 92939U106 209 3,340 SH   SOLE   37 0 0
Western Gas Equity Partners, LP COM UNT LTD PT 95825R103 38,802 1,171,571 SH   SOLE   3,340 0 199,611
Western Gas Partners LP COMUNT LP IN 958254104 583,103 13,665,412 SH   SOLE   971,960 0 1,661,592
Westlake Chem Corp Com COM 960413102 4,029 36,247 SH   SOLE   12,003,820 0 0
Williams Companies, Inc COM 969457100 359,180 14,448,123 SH   SOLE   36,247 0 753,117
Williams Partners L.P. COM UNIT LTD PAR 96949L105 626,943 18,209,209 SH   SOLE   13,695,006 0 2,858,612
WPX Energy Inc COM 98212B103 10,401 703,711 SH   SOLE   15,350,597 0 0
Xylem Inc. COM 98419M100 13 166 SH   SOLE   703,711 0 0