STATURE THROUGHOUT THE WORLD     

Bean RB 《Science (New York, N.Y.)》1928,67(1723):1-5

Tropic jungle life has an influence that decreases stature, and so has Arctic cold and waste. In each there is difficulty in procuring proper food, and discomfort in the extreme. The active life of the temperate zone with its comforts and abundant food supply produces the tallest statures. The greatest extremes of small stature are found among the Negrillos of Central Africa and the Aymaras of Central South America, in the jungles of excessive heat and poor food supply. Next to these come the Eskimos, Lapps and Siberians, with ice and excessive cold and poor food supply. On the other hand, the littoral and southern Baltic regions in Europe, the western part of Asia, eastern Africa, and the plains and pampas of the Americas with their active life, abundant food supply and temperate climate produce the tallest statures. Certain stocks may move into areas for which they are not fitted and remain for a time, and such conditions exist throughout the world to-day where recent movements of peoples have taken place, but ultimately there is a survival of the stock best fitted for the environment, and the unfitted stocks disappear by amalgamation, eradication or dispersal. Sea areas and probably sea food have an influence in reducing stature. The present Mediterranean peoples and the primordial British have small statures and so does Japan, yet they came from taller continental stocks. The Central Americans and Fuegians are smaller than the continental peoples near-by. The Malays and southern Asiaties are smaller than the peoples of the interior of the continent. Other instances might be cited. There is some evidence that the seaboard statures of the United States are less than those of the interior, but other factors enter here. Looked at in its broadest sense, environment molds the individual, selection retains the fittest under different environments, and heredity carries on the results.  相似文献   

Temporally unstable recurrence of earthquakes due to breaks in fractal scaling     

McCloskey J  Bean CJ 《Science (New York, N.Y.)》1994,266(5184):410-412

Observed sequences of large earthquakes are not consistent in either recurrence time or energy release; long-term prediction has been impossible even in areas, such as Parkfield, with well-defined recurrence intervals. The seismic gap hypothesis, which predicts characteristic earthquakes in areas of the circum-Pacific belt that have not produced recent great earthquakes, has also failed to predict the observed clustering of high-energy events. Models in which fractal scaling is broken at high magnitude predict that characteristic events and recurrence behavior will be unstable in time. The central predictions of these models are supported by recent observations at Landers and Big Bear in California.  相似文献   

Building a scientifically sound policy for protecting endangered species     

Eisner T  Lubchenco J  Wilson EO  Wilcove DS  Bean MJ 《Science (New York, N.Y.)》1995,269(5228):1231-1232

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Improved Cryopreservation of Sperm of Paddlefish (Polyodon spathula)     

Ákos  Horváth Béla  Urbányi Steven D.  Mims  William B.  Bean  Boris  Gomelsky Terrence R.  Tiersch 《Journal of the World Aquaculture Society》2006,37(4):356-362

Experiments were performed to improve protocols for sperm cryopreservation of paddlefish (Polyodon spathula), a species for which there has been limited study. The first experiment was conducted to investigate the effects of two extenders (modified Tsvetkova’s extender: mT and modified Hanks’ balanced salt solution: mHBSS) in combination with methanol (MeOH) and dimethyl sulfoxide in two concentrations (5 and 10%) on the postthaw motility and fertilization rates of cryopreserved sperm. The highest postthaw motility (85 ± 5%) was observed when sperm were frozen using mT extender with 10% MeOH as cryoprotectant. Extenders (P = 0.0018) and cryoprotectants (P = 0.0040) each had a significant effect on the postthaw motility of paddlefish sperm. The highest fertilization (80 ± 3%) was found when eggs were fertilized with sperm frozen with mT extender in combination with 10% MeOH. However, there was no significant difference among fertilization rates when MeOH was used as a cryoprotectant in either concentration or in combination with either mT or mHBSS extenders. In the second experiment, 4000 eggs were fertilized with the pooled contents of five straws of thawed sperm (total volume of 1.25 mL) using mT extender in combination with 5% MeOH, and hatch rates as high as 79 ± 5% were observed. A third experiment was also conducted to clarify the role of MeOH concentration; however, no significant difference was found among fertilization and hatch rates when either 5 or 10% MeOH was used as a cryoprotectant. These results suggest that MeOH is a safe and reliable cryoprotectant for freezing of paddlefish sperm and obtaining viable postthaw sperm for consistent fertilization and hatch rates. Further, this experimental protocol is relatively simple and applicable for commercial hatchery production of paddlefish.  相似文献   

Removal of surface lipids improves the functionality of commercial zein in viscoelastic zein-starch dough for gluten-free breadmaking     

Tilman J. Schober  Robert A. Moreau  Scott R. Bean  Daniel L. Boyle 《Journal of Cereal Science》2010,52(3):417-425

Maize prolamin (zein), together with starch, hydroxypropyl methylcellulose, sugar, salt, yeast and water can form wheat-like cohesive, extensible, viscoelastic dough when mixed above room temperature (e.g. 40 °C). This dough is capable of holding gas. However, it is excessively extensible, and when used for hearth-type rolls, it tends to become flat. Bench-scale defatting of zein with chloroform at room temperature significantly (P < 0.05) improved specific volume (4.5 ml/g vs. 3.3 ml/g) and shape of the rolls (width-to-height 2.0 vs. 3.9). The total lipid content determined by accelerated solvent extraction (100 °C, 69 bar, chloroform), however, only decreased from 8.0 to 6.6% due to this bench-scale defatting. Staining experiments with Naphthol Blue Black suggested that bench-scale defatting removed surface lipids from the zein particles, and thus facilitated their aggregation. Aggregation experiments with zein and water at 40 °C, and laser scanning confocal microscopy with zein-starch dough confirmed that zein particles aggregated more easily when surface-defatted. Dynamic oscillatory temperature sweeps demonstrated that surface-defatting lowered the temperature at which protein cross-linking occurred by 2 °C. This research can help to produce superior gluten-free bread and could also possibly contribute to the better understanding of wheat dough.  相似文献   

Phenolics in the bran of waxy wheat and triticale lines     

Ramakanth S. Jonnala  Sibel Irmak  Finlay MacRitchie  Scott R. Bean 《Journal of Cereal Science》2010,52(3):509-515

The present study was designed to determine total phenolic acid contents (TPC) and compositions of bran from newly developed near-isogenic waxy wheat and triticale translocation lines. Two waxy wheat sets, Svevo (durum) and N11 (bread wheat), consisting of partial and waxy null lines and four sets of triticales (GDS7, Trim, Rhino and Rigel) having translocations at 1A.1D and 1R.1D with high molecular weight glutenin subunits (HMW-GS) 5 + 10 and 2 + 12 were investigated. Similar to non-waxy wheat, ferulic acid was the predominant phenolic acid found in waxy wheats analyzed. Two other major phenolics include p-coumaric and vanillic acids followed by lesser quantities of syringic acid. Waxy lines had higher TPC than the parent line in the N11 set, whereas the Svevo set showed the opposite trend. TPC of waxy bread wheats were correlated with amylose fractions in which the order was complete waxy < double waxy nulls < single waxy nulls. Lines with HMW-GS 2 + 12 have lower TPC than other lines in each group of triticales, except the Trim set. TPC was negatively correlated (r = −0.41; p > 0.1) with bran yields in triticale lines studied, indicating that variation in phenolics was not only due to bran yields but also to genotypic differences.  相似文献   

Spatial and temporal distribution of the Asian fish tapeworm Bothriocephalus acheilognathi (Cestoda: Bothriocephalidea) in the Rio Grande (Río Bravo del Norte)     

Bean MG  Bonner TH 《Journal of aquatic animal health》2010,22(3):182-189

Recent collections of the Asian fish tapeworm Bothriocephalus acheilognathi in the Rio Grande have raised concern about the potential impacts on Rio Grande endemic and imperiled fishes. The objectives of this study were to determine distribution and definitive hosts of the Asian fish tapeworm within the Rio Grande drainage and to quantify occurrences and abundances. In total, 1,992 fish spanning 11 families were collected and examined for Asian fish tapeworms in the Rio Grande and the Pecos and Devils rivers. The parasite was collected from red shiners Cyprinella lutrensis, Tamaulipas shiners Notropis braytoni, sand shiners N. stramineus, river carpsuckers Carpiodes carpio, plains killifish Fundulus zebrinus, western mosquitofish Gambusia affinis, blue suckers Cycleptus elongatus, blacktail shiners Cyprinella venusta, proserpine shiners Cyprinella proserpina, and Manantial roundnose minnow Dionda argentosa, with the latter four species being new host records. Monthly collections of red shiners from Big Bend National Park exhibited prevalence levels above 15% in January-March and December and below 10% during April-June and October. With over 50% of the Rio Grande icthyofauna in Texas considered imperiled, the occurrence and pathological effects of the Asian fish tapeworm in combination with reduced water quantity and quality and increased habitat fragmentation are of concern for these taxa.  相似文献   

BID, BIM, and PUMA are essential for activation of the BAX- and BAK-dependent cell death program     

Ren D  Tu HC  Kim H  Wang GX  Bean GR  Takeuchi O  Jeffers JR  Zambetti GP  Hsieh JJ  Cheng EH 《Science (New York, N.Y.)》2010,330(6009):1390-1393

Although the proteins BAX and BAK are required for initiation of apoptosis at the mitochondria, how BAX and BAK are activated remains unsettled. We provide in vivo evidence demonstrating an essential role of the proteins BID, BIM, and PUMA in activating BAX and BAK. Bid, Bim, and Puma triple-knockout mice showed the same developmental defects that are associated with deficiency of Bax and Bak, including persistent interdigital webs and imperforate vaginas. Genetic deletion of Bid, Bim, and Puma prevented the homo-oligomerization of BAX and BAK, and thereby cytochrome c-mediated activation of caspases in response to diverse death signals in neurons and T lymphocytes, despite the presence of other BH3-only molecules. Thus, many forms of apoptosis require direct activation of BAX and BAK at the mitochondria by a member of the BID, BIM, or PUMA family of proteins.  相似文献   

Impact of different isolation procedures on the functionality of zein and kafirin     

Tilman J. Schober  Scott R. Bean  Michael Tilley  Brennan M. Smith  Brian P. Ioerger 《Journal of Cereal Science》2011,54(2):241-249

Commercial corn prolamin (zein) aggregates in water at elevated temperatures into an extensible, viscoelastic gluten-like substance. This specific functionality of zein can be used in the production of gluten-free bread from true dough systems and not from batters. The present study examined laboratory-scale isolation of such functional zein from dry milled corn. RP-HPLC indicated that successful isolation procedures resulted in relatively pure α-zeins, with a maximum ratio of (β + γ)/α-zeins of about 10%. In the present study, such functional zeins were obtained by using 70% ethanol as the extractant, without added alkali or reducing agent in the main extraction step. In contrast, films could be cast from a wider range of zein isolates, also with higher ratios of (β + γ)/α-zeins. Isolation of the analogous prolamin (kafirin) from dry milled sorghum required a more hydrophobic extractant such as 83% isopropanol to achieve partial functionality. Such kafirin was able to aggregate in warm water, preferably when a reducing agent was added; however, it quickly became firm and lost its extensibility. The present study suggests that hydrophobic interactions rather than disulfide bonds are the key to gluten-like functionality of zein and kafirin.  相似文献   

Sorghum Protein Extraction by Sonication and Its Relationship to Ethanol Fermentation     

Renyong Zhao  Scott R. Bean  Donghai Wang 《Cereal Chemistry》2008,85(6):837-842

The objectives of this research were to develop a rapid method for extracting proteins from mashed and nonmashed sorghum meal using sonication (ultrasound), and to determine the relationships between the levels of extractable proteins and ethanol fermentation properties. Nine grain sorghum hybrids with a broad range of ethanol fermentation efficiencies were used. Proteins were extracted in an alkaline borate buffer using sonication and characterized and quantified by size‐exclusion HPLC. A 30‐sec sonication treatment extracted a lower level of proteins from nonmashed sorghum meal than extracting the proteins for 24 hr with buffer only (no sonication). However, more protein was extracted by sonication from the mashed samples than from the buffer‐only 24‐hr extraction. In addition, sonication extracted more polymeric proteins from both the mashed and nonmashed samples compared with the buffer‐only extraction method. Confocal laser‐scanning microscopy images showed that the web‐like protein microstructures were disrupted during sonication. The results showed that there were strong relationships between extractable proteins and fermentation parameters. Ethanol yield increased and conversion efficiency improved significantly as the amount of extractable proteins from sonication of mashed samples increased. The absolute amount of polymeric proteins extracted through sonication were also highly related to ethanol fermentation. Thus, the SE‐HPLC area of proteins extracted from mashed sorghum using sonication could be used as an indicator for predicting fermentation quality of sorghum.  相似文献