A Field Method for Estimation of the Potential Evapotranspiration Rate

The integrals of the difference between wet and dry thermocouplereadings correlated closely with the daily amounts of evaporationfrom a Petri dish. A close relationship was also found betweenthe integral and the daily amount of transpiration of pot-grownbirch seedlings which were daily re-watered to near field capacity.     

若干因子对唐菖蒲花瓣提取物DPPH清除率的影响

采用DPPH·自由基分析法研究提取溶剂、提取温度和提取时间等因子对唐菖蒲鲜花花瓣中抗氧化物质活性的影响。结果表明,采用水(或极性较大的有机溶剂)作溶剂、70℃条件下、提取60min 后,花瓣提取物的DPPH·清除率较高;不同颜色的唐菖蒲花瓣相比,深红色花瓣提取物的DPPH·清除率最高;不同发育时期的唐菖蒲花瓣,其枯萎时期对DPPH·清除率最高。     

Calculation of a Toxic Potential Indicator Via Chinese-Language Material Safety Data Sheets

This article presents an approach to evaluating the toxic potential for products or materials using Chinese-language material safety data sheets (MSDSs). The toxic potential indicator (TPI) is one of many simple methods used to evaluate the environmental impact of toxins in products and materials. According to actual application experience in Taiwan, difficulties and problems arise in the preliminary implementation of TPI values calculated via Chinese-language MSDSs. Some adjustment techniques combining Chinese vocabulary conversion and unit transformation are proposed in this article to overcome these obstacles. The proposed procedures and evaluated results can serve as a basis for environmentally conscious product design, especially with regard to the choice of materials used in Chinese-speaking countries.     

Seroepidemiologic Survey of Potential Pathogens in Obligate and Facultative Scavenging Avian Species in California

Throughout the world, populations of scavenger birds are declining rapidly with some populations already on the brink of extinction. Much of the current research into the factors contributing to these declines has focused on exposure to drug residues, lead, and other toxins. Despite increased monitoring of these declining populations, little is known about infectious diseases affecting scavenger bird species. To assess potential infectious disease risks to both obligate and facultative scavenger bird species, we performed a serosurvey for eleven potential pathogens in three species of scavenging birds in California: the California condor (Gymnogyps californianus), turkey vulture (Cathartes aura) and golden eagle (Aquila chrysaetos). California condors were seropositive for avian adenovirus, infectious bronchitis virus, Mycoplasma gallisepticum, avian paramyxovirus-2, West Nile virus (WNV) and Toxoplasma gondii. Golden eagles were seropositive for avian adenovirus, Chlamydophila psittaci and Toxoplasma gondii, and turkey vultures were seropositive for avian adenovirus, Chlamydophila psittaci, avian paramyxovirus-1, Toxoplasma gondii and WNV. Risk factor analyses indicated that rearing site and original release location were significantly associated with a positive serologic titer to WNV among free-flying condors. This study provides preliminary baseline data on infectious disease exposure in these populations for aiding in early disease detection and provides potentially critical information for conservation of the endangered California condor as it continues to expand its range and encounter new infectious disease threats.     

Heart Rate Variability as an Indicator of Chronic Stress Caused by Lameness in Dairy Cows

Most experimental studies on animal stress physiology have focused on acute stress, while chronic stress, which is also encountered in intensive dairy cattle farming–e.g. in case of lameness–, has received little attention. We investigated heart rate (HR) and heart rate variability (HRV) as indicators of the autonomic nervous system activity and fecal glucocorticoid concentrations as the indicator of the hypothalamic–pituitary–adrenal axis activity in lame (with locomotion scores 4 and 5; n = 51) and non-lame (with locomotion scores 1 and 2; n = 52) Holstein-Friesian cows. Data recorded during the periods of undisturbed lying–representing baseline cardiac activity–were involved in the analysis. Besides linear analysis methods of the cardiac inter-beat interval (time-domain geometric, frequency domain and Poincaré analyses) non-linear HRV parameters were also evaluated. With the exception of standard deviation 1 (SD1), all HRV indices were affected by lameness. Heart rate was lower in lame cows than in non-lame ones. Vagal tone parameters were higher in lame cows than in non-lame animals, while indices of the sympathovagal balance reflected on a decreased sympathetic activity in lame cows. All geometric and non-linear HRV measures were lower in lame cows compared to non-lame ones suggesting that chronic stress influenced linear and non-linear characteristics of cardiac function. Lameness had no effect on fecal glucocorticoid concentrations. Our results demonstrate that HRV analysis is a reliable method in the assessment of chronic stress, however, it requires further studies to fully understand the elevated parasympathetic and decreased sympathetic tone in lame animals.     

Wastewater: A Potential Bioenergy Resource

Wastewaters are a rich source of nutrients for microorganisms. However, if left unattended the biodegradation may lead to severe environmental hazards. The wastewaters can thus be utilized for the production of various value added products including bioenergy (H₂ and CH₄). A number of studies have reported utilization of various wastewaters for energy production. Depending on the nature of the wastewater, different reactor configurations, wastewater and inoculum pretreatments, co-substrate utilizations along with other process parameters have been studied for efficient product formation. Only a few studies have reported sequential utilization of wastewaters for H₂ and CH₄ production despite its huge potential for complete waste degradation.     

A Decrease in the Rate of Human Aging in the 20th Century and its Potential Causes

Biophysics - Abstract—Since the middle of the 20th century, there has been a decrease in the rate of aging for developed countries with a maximum for ages 60–85 years. The calculation...     

Scavenging: how carnivores and carrion structure communities

Recent advances in the ecology of food webs underscore the importance of detritus and indirect predator-prey effects. However, most research considers detritus as an invariable pool and predation as the only interaction between carnivores and prey. Carrion consumption, scavenging, is a type of detrital feeding that should have widespread consequences for the structure and stability of food webs. Providing access to high-quality resources, facultative scavenging is a ubiquitous and phylogenetically widespread strategy. In this review, we argue that scavenging is underestimated by 16-fold in food-web research, producing inflated predation rates and underestimated indirect effects. Furthermore, more energy is generally transferred per link via scavenging than predation. Thus, future food-web research should consider scavenging, especially in light of how major global changes can affect scavengers.     

Heat Production Rate as an Indicator of the Ability of Plant Cell to Adapt to Environmental Conditions

The heat production rate in the suspension of unicellular alga (Chlorella vulgaris) was studied by the method of microcalorimetry during adaptation of the alga to stress conditions (NaCl and 45°C). The heat production rate slightly increased after the addition of 75 mM NaCl to cell suspension. A two-phase response was observed at 150 and 450 mM NaCl and at elevated temperature. The heat production rate was high during the first 3–4 h; then, it decreased and leveled off. This characteristic dramatically decreased at a high salt concentration (500 mM). Cell was unable to adapt to a high NaCl concentration (550 mM), which led to energy dissipation manifested in a high heat production rate. We conclude that the heat production rate, an integral indicator of plant cell activity can be used to assess plant cell adaptation to the impact of stress factors.     

Epinephrine: A Potential Neurotransmitter in Retina

Abstract: Dopamine (DA), norepinephrine (NE), and epinephrine (EPI) are present in rat retina. DA is the major catecholamine, whereas NE and EPI represent ∼5% of the DA content. DA is contained in a subpopulation of amacrine cells and has been the subject of numerous studies. We investigated the origin and properties of NE and EPI in retina. Following superior cervical ganglionectomy, there was a decrease in NE content, but no decrease in EPI or phenylethanolamine- N -methyltransferase (PNMT) activity. PNMT in retina has many of the substrate-specificity and inhibitor-sensitivity characteristics of other tissues. Enzyme activity is enhanced in newborn rats by treatment with dexamethasone. Exposure to a lighted environment increases retinal EPI in normal and superior cervical ganglionectomized rats. EPI content increased for more than 2 h in a lighted environment. We conclude that most of the NE is contained within the sympathetic neurons that innervate the eye from the superior cervical ganglion, whereas EPI is contained in retinal elements that are responsive to photic stimulation.     

壳聚糖对羟基自由基的清除作用研究

通过Fenton体系模拟了体内羟基自由基,并借助原子力显微镜（AFM）和通过荧光实验分别定性和定量研究了壳聚糖（CS）对羟基自由基的清除作用。通过AFM对红细胞成像来观察细胞的整体表面结构和微观结构,根据平均粗糙度和细胞微观结构的有序性来说明CS对羟基自由基的清除;由荧光实验中荧光强度的改变来说明不同浓度和不同分子量的CS清除自由基的效率。两种测量手段都一致地表明了CS能有效地清除自由基,而且清除效率随着CS浓度的增大而升高,随着CS分子量的增大而降低。     

Emoticon-Based Ambivalent Expression: A Hidden Indicator for Unusual Behaviors in Weibo

Recent decades have witnessed online social media being a big-data window for testifying conventional social theories quantitatively and exploring much detailed human behavioral patterns. In this paper, by tracing the emoticon use in Weibo, a group of hidden “ambivalent users” are disclosed for frequently posting ambivalent tweets containing both positive and negative emotions. Further investigation reveals that this ambivalent expression could be a novel indicator of many unusual social behaviors. For instance, ambivalent users with the female as the majority like to make a sound in midnights and at weekends. They mention their close friends frequently in ambivalent tweets, which attract more replies and serve as a more private communication way. Ambivalent users also respond differently to public affairs from others and demonstrate more interests in entertainment and sports events. Moreover, the sentiment shift in ambivalent tweets is more evident than usual and exhibits a clear “negative to positive” pattern. The above observations, though being promiscuous seemingly, actually point to the self-regulation of negative mood in Weibo, which could find its basis from the traditional emotion management theories in sociology but makes an important extension to the online environment in this study. Finally, as an interesting corollary, ambivalent users are found connected with compulsive buyers and turn out to be perfect targets for online marketing.     

Potential of Spartina maritima in Restored Salt Marshes for Phytoremediation of Metals in a Highly Polluted Estuary

Sedimentary abiotic environment, and concentration and stock of nine metals were analyzed in vegetation and sediments to evaluate the phytoremediation capacity of restored Spartina maritima prairies in the highly polluted Odiel Marshes (SW Iberian Peninsula). Samples were collected in two 10 –m long rows parallel to the tidal line at two sediments depths (0–2 cm and 2–20 cm). Metal concentrations were measured by inductively coupled plasma spectroscopy. Iron, aluminum, copper, and zinc were the most concentrated metals. Every metal, except nickel, showed higher concentration in the root zone than at the sediment surface, with values as high as ca. 70 g Fe kg^–1. The highest metal concentrations in S. maritima tissues were recorded in its roots (maximum for iron in Spartina roots: 4160.2 ± 945.3 mg kg^–1). Concentrations of aluminum and iron in leaves and roots were higher than in superficial sediments. Rhizosediments showed higher concentrations of every metal than plant tissues, except for nickel. Sediment metal stock in the first 20 cm deep was ca. 170.89 t ha^–1. Restored S. maritima prairies, with relative cover of 62 ± 6%, accumulated ca. 22 kg metals ha^–1. Our results show S. maritima to be an useful biotool for phytoremediation projects in European salt marshes.