Assessment of heavy metal in the water,sediment, and two edible fish species of Jamshedpur Urban Agglomeration,India with special emphasis on human health risk

The city of Jamshedpur, nicknamed the “industrial capital of Jharkhand,” is one of the oldest industrial settlements in India, nestled amidst the mineral-rich Chota Nagpur plateau, with its diverse tribal population. Heavy metal contamination from industrialization and urbanization can pose a serious health risk to the resident population of the city. Metal concentrations in water and sediment of various water bodies (rivers, canals, and lakes) were determined using ICP-MS. Pollution indices indicate heavy metal contamination at Jamshedpur Urban Agglomeration, mainly because of Cr (23–1111.6 mg/kg), Hg (0.08–4.11 mg/kg), and Pb (5.2–248 mg/kg). Labeo rohita and Punitus sarara, the two popular edible fishes, also have high concentration of Cr, Hg, and Pb. Health risk to human population due to consumption of metal contaminated edible fishes (L. rohita and P. sarara) was determined by target hazard quotient (THQ) and hazard index (HI). THQ value of fish consumption (most popular protein supplement in the area) was found higher for Cr and Pb when compared with previous literature on fish consumption. Also, HI value ranged from 1.4 to 3.9, suggesting that the children have higher health risks than adults, due to consumption of metal contaminated fishes (especially L. rohita).     

Eveningness is associated with higher risk-taking in dangerous driving situations

Inclination toward eveningness is often associated with risky behavior. But the existing studies are scarce, inconsistent and usually limited to self-reported measures. We sought to investigate in young adults whether morningness-eveningness is associated with risky behavior in dangerous driving situations, with self-reported drunk driving and with alcohol consumption. Results show that, indeed, inclination toward eveningness is associated with these risky behaviors. We also demonstrate a link between morningness-eveningness and sensation seeking. Therefore, young adults with a tendency toward eveningness might be more at risk to face negative consequences of alcohol abuse or to be involved in a road accident.     

Feeding ecology of mackerel and dietary overlap with herring in Icelandic waters

The Northeast Atlantic mackerel (Scomber scombrus) has been extending its summer feeding distribution north and west, including around Iceland, since around 2006. The objective of this study is to quantify the weight gain and total food consumption of mackerel and to evaluate the food competition between mackerel and herring (Clupea harengus) feeding in the marine ecosystem around Iceland during the summers 2009–2011. Mackerel feeding in Icelandic waters gained around 43% on average in weight during these summers. Based on swept-area abundance estimates of mackerel from an international survey in 2011 and available estimates of food conversion efficiency in mackerel, the weight gain in Icelandic waters in 2011 corresponded to a total consumption of around 3.4 (2.4?4.5) million tonnes. Overall, 98% of 2314 mackerel, 91% of 398 Icelandic summer-spawning herring and 96% of 424 Norwegian spring-spawning herring stomachs, collected over the summers 2009?2011, contained food. The mean weight of the stomach content of mackerel was higher than for herring in all the years. While the stomach content weight of mackerel was generally highest in southeastern and southwestern areas, it was highest for herring in western, eastern and northern areas. Analysis of stomach contents showed that Copepoda were the most important food of mackerel in most areas, while Copepoda and Euphausiacea were the most important food items for herring. Fish prey contributed a higher proportion in stomachs of mackerel than herring, although relatively low for both species.     

Food consumption, body mass and fat deposition in captive regent honeyeaters, Xanthomyza phrygia (Meliphagidae), during the non-breeding season

The regent honeyeater (Xanthomyza phrygia) is a large endangered honeyeater from eastern and south-eastern Australia. Little is known about the ecology of this bird during the autumn-winter period, when it is absent from its breeding areas. In this study, food consumption and body condition of captive regent honeyeaters were studied during this period. Nectar was the dominant component of the regent honeyeaters diet and varied significantly throughout the study, peaking in early July. Fruit and mealworm consumption also showed significant seasonal shifts with maxima in late June and early March, respectively. In general, immature birds consumed significantly more protein-rich food than adults. The average body mass of the male birds varied significantly with season. Female birds did not show a significant seasonal change in body mass but, similarly to males, attained their highest mass in late April. Fat deposition changed significantly over months, with highest levels of fat recorded from late April until late June. These seasonal trends, independent of food abundance, may suggest that body condition within this species is controlled endogenously.Communicated by F. Bairlein     

Increased working capacity with hyperoxia in humans

The purpose of the study was to examine the influence of oxygen-breathing on maximal oxygen uptake (VO2max) and submaximal endurance performance. Six young women and five men rode a cycle-ergometer while breathing compressed air (normoxia, NOX) or a 55% O2 in N2 mixture (hyperoxia, HOX). The VO2max increased significantly by 12% (P less than 0.01) with HOX in the women but not in the men (+4%; nonsignificant). Maximal heart rate was also increased with HOX in the women but not in the men. Endurance time during work to exhaustion at 80% of normoxic VO2max was 41% longer in HOX than in NOX (P less than 0.025) with no significant difference between the men and the women. The variation among individuals was large. The oxygen uptake and respiratory quotient were not different in the two endurance tests, but pulmonary ventilation (VE) and blood lactate concentration were lower in HOX than in NOX, especially during the latter part of the task. Plasma base deficit (BDpl) increased initially by 3.5 mmol.l-1 during HOX and then stabilized. In NOX, a continuous increase was seen and the change was more than twice as large. Relative to BDpl, VE was higher in HOX than in NOX indicating a more efficient ventilatory compensation of the metabolic acidosis. The reduced ventilatory demand and lower metabolic acidosis in HOX in combination with lower relative exercise intensity may have contributed to the longer time to exhaustion. However, the pattern of individual variation suggested that other mechanisms were also involved.     

The effect of oxygen on the growth and acid production of Streptococcus mutans and Streptococcus sanguis

Abstract Pure cultures of Streptococcus mutans NCTC 10499 and Streptococcus sanguis ATCC10556 were grown in a glucose-limited chemostat under varying concentrations of oxygen in the gas phase. Both streptococci consumed large amounts of oxygen by the partial oxidation of sugars, thus maintaining an anaerobic environment. With increasing oxygen concentrations the degradation products from glucose become more oxidized. Ethanol gradually disappeared from the culture fluid while the acetate concentration increased. In the case of S. sanguis , the products became even more oxidized at higher oxygen concentrations, and carbon dioxide was formed instead of formate. Sudden increase in the oxygen concentration in the gas phase caused elevated oxygen tensions in the cultures, which led to a decrease in the growth rate of the streptococci.     

Effects of autoclave-induced carbohydrate hydrolysis on the growth ofBeta vulgaris cells in suspension

Media of de Greef & Jacobs (1979) were autoclaved either with all the nutrient components in a single vessel (medium 1) or with the following components in separate vessels: FeNa–EDTA+CaCl₂ (medium 2), FeNa–EDTA+NaH₂PO₄ (medium 3) or sucrose (medium 4). Medium 5 was prepared by autoclaving FeNa–EDTA+NaH₂PO₄ and sucrose in two separate vessels. It was found that the dry mass yield of cell suspensions ofBeta vulgaris was lowest in medium 1, followed by media 2 and 3. There was no significant difference among media 3, 4, and 5.The plot of dry mass yield of the cell suspensions against the rates of cyanide-initiated oxygen consumption which indicate the extent of carbohydrate hydrolysis of the media during autoclaving, indicated the presence of a threshold rate of about 17–20 nmol ml^–1 min^–1. Dry mass yield of the suspensions decreased rapidly when the rate exceeded this value.For media with glucose as the source of carbohydrate, the rate of cyanide-initiated oxygen consumption exceeded the threshold value by a factor of 1.5 to 2, depending on the volume of the media autoclaved.Abbreviations FeNa-EDTA ferric monosodium ethylenediamine-tetraacetic acid     

河流景观生态服务供给与需求/消费的互馈机制

河流景观系统孕育了人类文明,为人类社会提供类型多样的生态系统服务。其本身是一个自然景观过程和社会经济过程高度耦合的社会-生态系统,具有极高的空间异质性、时间动态和鲜明的组织尺度等级结构。当前,对河流景观系统这种特点所决定的生态系统服务供给与需求/消费互馈的机制研究不够深入,普遍缺乏从过程角度刻画生态服务供给与需求/消费互馈关系及其时空异质性和尺度特征。生态服务供给、需求和消费产生于社会-生态系统,是社会-生态耦合的纽带。阐述了河流景观生态服务供给和需求/消费的时空异质性,阐释了它们时空耦合机制和尺度特征,梳理了当前对生态服务供给、需求/消费互馈机理研究的不足。认为未来需要在社会-生态系统的框架下,从景观结构和生态过程出发,融合景观生态过程和社会过程来深入认识河流景观系统的生态服务供给与区内人类对生态服务的需求/消费之间的互馈机制。未来应重点关注：（1）河流景观结构和过程决定的生态服务供给和消费的空间分异及驱动机制;（2）河流生态服务传输的自然和人文载体及其耦合格局;（3）将生态服务需求/消费通过景观结构和生态过程对生态服务供给的反馈融入生态服务评估的方法框架,研发基于生态服务供给和需求/消费的社会-生态互馈过程模型。     

Female control of sperm ejection and retention in the cornsilk fly Euxesta eluta (Diptera: Ulidiidae)

Promiscuous mating systems provide the opportunity for females to bias fertilization toward particular males. However, distinguishing between male sperm competition and active female sperm choice is difficult for species with internal fertilization. Nevertheless, species that store and use sperm of different males in different storing structures and species where females are able to expel all or part of the ejaculates after copulation may be able to bias fertilization. We report a series of experiments aimed at providing evidence of female sperm choice in Euxesta eluta (Hendel), a species of ulidiid fly that expels and consumes ejaculates after copulation. We found no evidence of greater reproductive success for females mated singly, multiply with the same male, or mated multiply with different males. Female E. eluta possesses two spherical spermathecae and a bursa copulatrix for sperm storage, with a ventral receptacle. There was no significant difference in storing more sperm in spermathecae 24 h after copulation than immediately after copulation. Females mated with protein-fed males had greater reproductive success than similar females mated to protein-deprived males. Protein-fed females prevented to consume the ejaculate, retained more sperm when mated to protein-fed males than when mated to protein-deprived males. Our results suggest that female E. eluta can exert control of sperm retention of higher quality males through ejaculate ejection.     

Healing while parasitized: impact of a naturally-occurring nematode during energy-intensive wound-healing in a beetle

The rigours of the daily lives of insects sometimes lead to minor injuries and wounds, which must be healed to avoid entry of pathogens and to resume normal function. Such healing requires energy, which must be diverted from other bodily reserves. What happens if energy reserves are already low, as would occur in individuals coping with internal parasites? This question is addressed in the presemt study, using horned passalus beetles (Odontotaenius disjunctus) and their naturally-occurring nematode Chondronema passali. Oxygen consumption rates are tested at rest, as well as after an experimental wound is applied, to evaluate energy requirements of wound-healing in parasitized and nonparasitized hosts. Furthermore, wound-healing rates are visually tracked with a numerical scoring system to directly measure the cost of parasitism on healing. At rest, parasitized beetles show no elevation in respiration (oxygen consumption). After wounding, the oxygen consumption of parasitized beetles is 10% higher than that in nonparasitized beetles. Beetles with moderate- to heavy worm burdens have slower healing than those with few or no nematodes. These results show that this parasite carries little cost to the host during day-to-day activities, whereas, during times of immediate energy demand, there is a cost; hosts require more energy to repair wounds, and the wounds take longer to close. This conclusion leads to the question of whether this parasite is truly benign, and how many other apparently benign parasites, in insects or other animals, have similar ‘hidden’ effects.