Trace element concentrations in skin of free-ranging bottlenose dolphins (Tursiops truncatus) from the southeast Atlantic coast

Concentrations of trace elements (Al, As, Ba, Be, Cd, Co, Cr, Cu, Fe, Li, Mn, Ni, Pb, Sb, Se, Sn, Tl, U, V, Zn) and total mercury (THg) were determined in skin samples collected from free-ranging bottlenose dolphin (Tursiops truncatus) populations. Dolphins were captured in the estuarine waters of Charleston (CHS), South Carolina (n=74) and the Indian River Lagoon (IRL), Florida (n=75) during 2003, 2004 and 2005. A subset of the skin tissue samples were used to determine methylmercury (MeHg) levels in CHS (n=17) and IRL (n=8) bottlenose dolphins. Distributions of trace element concentrations by age (adult vs. juvenile), gender (male vs. female) and study area (CHS vs. IRL) were examined. In general, higher elemental skin concentrations were found in CHS adult males than those of IRL adult males, except for THg and MeHg. For CHS dolphins, adult females showed significantly higher THg levels than juvenile females while higher Mn levels were found in juvenile females. For IRL dolphins, adult males showed significantly higher As concentrations than that in juvenile males and females while higher Co and V levels were found in juvenile males than adult males. Of all elements measured in this study, significantly higher levels of Fe, Se and Zn concentrations in skin tissue of both dolphin populations were similar to other studies reported previously. Percentage of MeHg/THg in skin tissue of CHS and IRL dolphin was about 72% and 73%, respectively. Dietary levels of trace elements may play an important role in contributing to concentration differences for As, Co, Mn, Sb, Se, THg and Tl between CHS and IRL dolphins. Total Hg concentrations were significantly correlated with the age of CHS dolphins, while an inverse relationship was detected for Cu, Mn, Pb, U and Zn. The only significant correlation found between trace element concentration and IRL dolphins' age was Mn. Geographic differences in several trace element concentrations (As, Co, Mn, Sb, Se, THg and Tl) in skin tissue may be potentially useful to discriminate between dolphin populations and is a possibility that warrants further investigation.     

用SPC开启工厂能量

<正>随着产品召回等质量问题的层出不穷,越来越多的制造企业开始寻求统计过程控制工具的帮助。作为普通的消费者,我们在日常采购活动中都有过遭遇问题产品、缺陷产品的经历。小到儿童玩具上的零件不全,大到新买的汽车开到路上无端抛锚等等。产品缺陷已经成为困扰消费者的核心问题,同时也是制造企业面临的巨大隐忧。     

Embedded method for indexing control arrays in multimode conservative codes for holographic storage

In multimode conservative codes for holographic storage, an unconstrained m x n binary array S of source data is added to a set of (m + 1)(n + 1) control arrays to form the selection set, which is guaranteed to contain at least one conservative array of strength at least t, such that each row and each column of the output array contain at least t transitions. To be able to retrieve the original source data array S during the decoding process, at least[log2(m + 1)(n + 1)]redundant bits are necessary to index the (m + 1)(n + 1) control arrays. Presented is a method for embedding the index information of the control arrays into the encoded arrays in a manner which requires only [log2(m + 1)]+[log2(n + 1)]redundant bits, thereby attaining high coding efficiency.     

Preliminary evaluation of a new high power diode laser

A high-powered semiconductor diode laser (805 nm) has recently been developed for medical use. The laser-tissue interactions of this wavelength have been compared with Nd:YAG (1064 nm). When used in the contact mode, the extent of tissue vaporization and zones of thermal necrosis produced by these two lasers were similar. The diode laser was also an effective and haemostatic laser scalpel. This compact laser unit has potential advantages over existing Nd:YAG lasers.     

The radiographic edge scattering distortion

Previously described scattering based edge distortions in optical density scans obtained from a neutron radiographic knife-edge image have been here confirmed using analog Monte Carlo simulation. In an attempt to estimate the effects of additional object scatter on such artifacts, the effect on the edge response of diffusely incident neutrons has been determined both empirically and by Monte Carlo simulation. The diffuse neutron incidence has been found to diminish the relative magnitude of the distortion, offering explanation for the infrequent observation of the corresponding edge scattering halo artifacts. The potential of this edge distortion as a diagnostic indicator of the buildup factor in radiography is suggested and examined.     

Molecular surveillance of shiga toxigenic Escherichia coli O157 by PulseNet USA

PulseNet USA is the national molecular subtyping network system for foodborne disease surveillance. Sixty-four public health and food regulatory laboratories participate in PulseNet USA and routinely perform pulsed-field gel electrophoresis of Shiga toxigenic Escherichia coli isolated from humans, food, water, and the environment on a real-time basis. Clusters of infection are detected in three ways within this system: through rapidly alerting the participants in the electronic communication forum, the PulseNet Web conference; through cluster analysis by the database administrators at the coordinating center at the Centers for Disease Control and Prevention of the patterns uploaded to the central server by the participants; and by matching profiles of strains from nonhuman sources with recent human uploads to the national server. The strengths, limitations, and scope for future improvements of PulseNet are discussed with examples from 2002. In that year, notices of 30 clusters of Shiga toxigenic E. coli O157 infections were posted on the Web conference, 26 of which represented local outbreaks, whereas four were multistate outbreaks. Another 27 clusters were detected by central cluster detection performed at the Centers for Disease Control and Prevention, of which five represented common source outbreaks confirmed after finding an isolate with the outbreak pattern in the implicated food. Ten food isolates submitted without suspicion of an association to human disease matched human isolates in the database, and an epidemiologic link to human cases was established for six of them.     

Method for separating intramolecular and intermolecular interactions which influence polymer glass temperatures

It is shown that the glass temperature (T_g) for homopolymers of the type ? CH₂? CXY? can be expressed by a simple additive equation involving two terms: (1) a parameter E which is directly related to the molar cohesion energy and (2) a parameter E_s^* which is a measure of restricted rotation about valence bonds. E_s^*, at least for a large number of polymers, is related to the Mark-Houwink K_θ value (as measured in θ solvents at T_θ) via anti-log E_s^* ∝ 1/K_θ^2/3. It is also shown that for homologous series [e.g., poly(n-alkyl methacrylates)], there is a constant relationship between E and antilog E_s^*. The T_g values for copolymers may be estimated by a simple weighted (via mole fraction) summation of the E and E_s^* values of the components. When used in this form, a linear variation between T_g and composition is assumed, which may not be strictly correct but still yields useful approximations.     

Integrated furfural production as a renewable fuel and chemical platform from lignocellulosic biomass

Furfural is a natural precursor to furan‐based chemicals and has the potential to become a major renewable platform chemical for the production of biochemicals and biofuels. However, current industrial furfural production relies on relatively old and inefficient strategies that have hindered its capacity, and low production yields have strongly diminished its competitiveness with petroleum‐based alternatives in the global market. This mini‐review provides a critical analysis of past and current progress to enhance furfural production from lignocellulosic biomass. First, important chemical and fuel products derived from the catalytic conversion of furfural are outlined. We then discuss the importance of developing integrated production strategies to co‐produce furfural with other valuable chemicals. Furfural formation and loss chemistries are explored to understand effective methods to improve furfural yields from pentosans. Finally, selected relevant commercial and academic technologies that promise to improve lignocellulosic furfural production are discussed. © 2013 Society of Chemical Industry