The Impact of Energy Management Control Systems on Energy Efficiency in the German Manufacturing Industry

Although previous studies point to much (untapped) potential for energy efficiency enhancement in industry, empirical research that adapts findings of environmental control to the context of energy management remains widely neglected. Specifically, previous environmental research suggests that the implementation of energy management control systems (EnMCS) could be an effective lever for companies to enhance their production systems and operations toward energy efficiency. Yet, empirical evidence for this theoretical proposition is rather missing; thus, debate continues regarding whether the high investments to set up a comprehensive EnMCS pay off in the long run. Based on a sample of 236 German manufacturing companies, this study combines primary data that capture the configuration of EnMCS with secondary data that were used to calculate energy efficiency. The results provide evidence that the extent of EnMCS implementation positively relates to firms’ energy efficiency. Findings from additional moderation analysis suggest that companies might enhance the relationship of EnMCS and energy efficiency performance by establishing a full‐time energy manager or by using external energy consulting support.     

Impact of Interruptions on Schedule Execution in Flexible Manufacturing Systems

Finite capacity scheduling software packages provide a detailed advance plan of production events. However, the execution of this advance plan is disrupted by a myriad of unanticipated interruptions, such as machine breakdowns, yield variations, and hot jobs. The alternatives available to respond to such interruptions include modifying the existing schedule, regenerating the complete schedule, or doing nothing and letting the production system gradually absorb the impact of the interruption. This article reports on a simulation study aimed at understanding the impact of an interruption on a schedule in order to build a knowledge base for intelligent selection of a response from a set of alternatives. The results of the experimental study are used to identify significant major factors and their interactions. The results are discussed to draw insights into the performance of a flexible manufacturing system following an interruption. The causes leading to particular performance anomalies are extensively discussed and mechanisms for propagation and absorption of the effect of interruptions in manufacturing systems are inferred. Practical implications for the development and implementation of schedules are deduced and areas for further research proposed. This study provides the groundwork necessary to proceed with the development of strategies for responding to interruptions.     

Impact of Forest Harvesting on Trophic Structure of Eastern Canadian Boreal Shield Lakes: Insights from Stable Isotope Analyses

Perturbations on ecosystems can have profound immediate effects and can, accordingly, greatly alter the natural community. Land-use such as forestry activities in the Canadian Boreal region have increased in the last decades, raising concerns about their potential impact on aquatic ecosystems. The objective of this study was to evaluate the impact of forest harvesting on trophic structure in eastern Canadian Boreal Shield lakes. We measured carbon and nitrogen stable isotopes values for aquatic primary producers, terrestrial detritus, benthic macroinvertebrates, zooplankton and brook trout (Salvelinus fontinalis) over a three-year period in eight eastern Boreal Shield lakes. Four lakes were studied before, one and two years after forest harvesting (perturbed lakes) and compared with four undisturbed reference lakes (unperturbed lakes) sampled at the same time. Stable isotope mixing models showed leaf-litter to be the main food source for benthic primary consumers in both perturbed and unperturbed lakes, suggesting no logging impact on allochthonous subsidies to the littoral food web. Brook trout derived their food mainly from benthic predatory macroinvertebrates in unperturbed lakes. However, in perturbed lakes one year after harvesting, zooplankton appeared to be the main contributor to brook trout diet. This change in brook trout diet was mitigated two years after harvesting. Size-related diet shift were also observed for brook trout, indicating a diet shift related to size. Our study suggests that carbon from terrestrial habitat may be a significant contribution to the food web of oligotrophic Canadian Boreal Shield lakes. Forest harvesting did not have an impact on the diet of benthic primary consumers. On the other hand, brook trout diet composition was affected by logging with greater zooplankton contribution in perturbed lakes, possibly induced by darker-colored environment in these lakes one year after logging.     

The Influence of the API Properties on the ODTs Manufacturing from Co-processed Excipient Systems

Directly compressible co-processed excipient systems facilitate orodispersible tablets (ODTs) manufacturing. Despite several excipient systems available, it is reported that the incorporation of high drug dose into the tablet mass may negatively affect both disintegration and mechanical properties. Therefore the influence of drug properties on the quality of orodispersible tablets was investigated. Fast dissolving tablet matrix was made of a co-processed excipient system F-Melt. Two grades of F-Melt that differed in composition, particle shape, and specific surface area were used to form tablet matrix. Ibuprofen, diclofenac sodium, and diltiazem hydrochloride were chosen as model drugs of different physicochemical properties such as solubility, particle size, and shape. Ninety formulations containing 12.5, 25, or 50 wt% of the model drug and F-Melt type C or M were prepared by direct compression. The quality of tablets was examined on the base of disintegration time, wetting time, mechanical resistance and texture analysis. The results showed that F-Melt grade, drug solubility, and its dose had an influence on the quality of tablets. From ninety formulations prepared, only four batches containing F-Melt type C and 12.5 wt% of ibuprofen, diclofenac sodium, or diltiazem hydrochloride could be classified as ODTs. Their disintegration time ranged from 41 to 144 s. In the case of F-Melt type M, tablets disintegrating within 101 s of friability below 1% could be prepared only if 12.5 wt% of diclofenac sodium was incorporated into the tablet mass.Key words: diclofenac sodium, diltiazem hydrochloride, direct compression, F-Melt, ibuprofen, ODTs     

Laser Impact on Bacterial ATP: Insights into the Mechanism of Laser-Bacteria Interactions

The mechanisms of laser action on bacteria are not adequately understood. Here, an attempt has been made to study the fluctuation in ATP (adenosine triphosphate) concentration following laser irradiation from a pulsed Nd:YAG laser on a marine biofilm-forming bacterium Pseudoalteromonas carrageenovora. A stationary phase bacterial suspension (density 10^7-8 ml^{m 1}) was exposed to pulsed laser irradiations at a fluence of 0.1 J cm^{m 2} (pulse width 5 ns, repetition rate 10 Hz) for different durations, ranging from 2 s to 15 min. The total viable count (TVC) and ATP concentration of the irradiated samples were determined immediately after the laser irradiation. While the maximum reduction in the TVC observed with respect to the control was 59% immediately after 15 min irradiation, the ATP concentration showed a reduction of about 86% for the same duration. The ATP concentration showed an abrupt reduction from 3 min of laser irradiation and continued to reduce significantly with increasing duration of irradiation. Thus, 3 min irradiation at a fluence of 0.1 J cm^{m 2} is considered as an approximate threshold for ATP production in this bacterium. As the decreased level of ATP production continued, bacterial mortality resulted. The reduction in ATP production could be due to damage caused by the laser irradiations on bacterial metabolic processes such as cellular respiration.     

逆转座子对灵长目动物基因组结构的影响

逆转座子(retroposon)是动物基因组中一类可移动的元件,它们首先通过转录产生一个RNA拷贝,然后利用逆转录酶将该RNA拷贝逆转录为c DNA后,再插入到基因组的新位点上。逆转座子在动物基因组中含量极为丰富,种类也很繁多,并随着动物进化在基因组中不断扩增。它们可通过形成插入突变、侧翼序列转导、基因逆转座、DNA断裂与修复、异常重组等机制对动物基因组结构的稳定性产生重要影响,并成为推动基因组进化的重要动力。本文综述了灵长目动物主要的逆转座子类型及其对基因组结构的影响方式,从而为深入理解逆转座子在灵长目动物基因组中的功能及灵长目动物的进化提供参考。     

The Impact of the Demographic Transition on Dengue in Thailand: Insights from a Statistical Analysis and Mathematical Modeling

Background

An increase in the average age of dengue hemorrhagic fever (DHF) cases has been reported in Thailand. The cause of this increase is not known. Possible explanations include a reduction in transmission due to declining mosquito populations, declining contact between human and mosquito, and changes in reporting. We propose that a demographic shift toward lower birth and death rates has reduced dengue transmission and lengthened the interval between large epidemics.

Methods and Findings

Using data from each of the 72 provinces of Thailand, we looked for associations between force of infection (a measure of hazard, defined as the rate per capita at which susceptible individuals become infected) and demographic and climactic variables. We estimated the force of infection from the age distribution of cases from 1985 to 2005. We find that the force of infection has declined by 2% each year since a peak in the late 1970s and early 1980s. Contrary to recent findings suggesting that the incidence of DHF has increased in Thailand, we find a small but statistically significant decline in DHF incidence since 1985 in a majority of provinces. The strongest predictor of the change in force of infection and the mean force of infection is the median age of the population. Using mathematical simulations of dengue transmission we show that a reduced birth rate and a shift in the population''s age structure can explain the shift in the age distribution of cases, reduction of the force of infection, and increase in the periodicity of multiannual oscillations of DHF incidence in the absence of other changes.

Conclusions

Lower birth and death rates decrease the flow of susceptible individuals into the population and increase the longevity of immune individuals. The increase in the proportion of the population that is immune increases the likelihood that an infectious mosquito will feed on an immune individual, reducing the force of infection. Though the force of infection has decreased by half, we find that the critical vaccination fraction has not changed significantly, declining from an average of 85% to 80%. Clinical guidelines should consider the impact of continued increases in the age of dengue cases in Thailand. Countries in the region lagging behind Thailand in the demographic transition may experience the same increase as their population ages. The impact of demographic changes on the force of infection has been hypothesized for other diseases, but, to our knowledge, this is the first observation of this phenomenon. Please see later in the article for the Editors'' Summary     

On the Dependability Design of Manufacturing Information Systems

In computer integrated manufacturing environments, dependability is a crucial attribute for the production management and control information system, which should be carefully assessed during system design. This paper discusses a global approach for assessment of the dependability of industrial information systems, covering all the phases of a study, from initial system modeling to dependability analysis and evaluation. After the presentation of the modeling concepts and tools, the paper focuses on the dependability evaluation. Two complementary algorithms are discussed, one based on the device stage method and the other on the automatic derivation of analytical expressions for the state probabilities and their symbolic evaluation. The central feature of these algorithms is their ability to deal with nonexponential stochastic processes, a fundamental requirement for this class of systems.     

Supervisory Control of Functionally-Expandable Manufacturing Systems

Supervisory controllers have traditionally coordinated the various resources of manufacturing systems, such as flexible manufacturing workcells, for the production of a priori set families of part types. This paper expands on this capability by allowing the control of the production of new part types side by side with previously defined and planned for nominal part types. The proposed basic workcell supervisory-control approach advocates the use of a pair of non-communicating independent supervisors, synthesized individually but working in concert, to achieve the production of existing and new part types: nominal and complementary supervisors, respectively. The nominal supervisor is responsible for controlling the behavior of the nominal system, producing the set of a priori planned-for part types, whereas the complementary supervisor controls the flow of the a priori unplanned-for new part types.     

Sources of Biomass Feedstock Variability and the Potential Impact on Biofuels Production

Terrestrial lignocellulosic biomass has the potential to be a carbon neutral and domestic source of fuels and chemicals. However, the innate variability of biomass resources, such as herbaceous and woody materials, and the inconsistency within a single resource due to disparate growth and harvesting conditions, presents challenges for downstream processes which often require materials that are physically and chemically consistent. Intrinsic biomass characteristics, including moisture content, carbohydrate and ash compositions, bulk density, and particle size/shape distributions are highly variable and can impact the economics of transforming biomass into value-added products. For instance, ash content increases by an order of magnitude between woody and herbaceous feedstocks (from ～0.5 to 5 %, respectively) while lignin content drops by a factor of two (from ～30 to 15 %, respectively). This increase in ash and reduction in lignin leads to biofuel conversion consequences, such as reduced pyrolysis oil yields for herbaceous products as compared to woody material. In this review, the sources of variability for key biomass characteristics are presented for multiple types of biomass. Additionally, this review investigates the major impacts of the variability in biomass composition on four conversion processes: fermentation, hydrothermal liquefaction, pyrolysis, and direct combustion. Finally, future research processes aimed at reducing the detrimental impacts of biomass variability on conversion to fuels and chemicals are proposed.© 2015 Battelle Energy Alliance, LLC, contract manager for Idaho National Laboratory.     

Environmental Variability and Its Impact on the Reproductive Cycle of Antarctic Krill

"Recruitment potential" in Antarctic krill in the Palmer Long-TermEcological Research (LTER) study region west of the AntarcticPeninsula varied significantly over the 7-yr time series betweenJanuary 1993 and January 1999. Timing of ovarian maturation,the percent of the population reproducing, and individual reproductiveoutput (batch volume, embryo diameter) were measured. Indiceshave been developed to quantify the timing and intensity ofreproduction in Antarctic krill. One finding important to estimatesof population fecundity for this long-lived species is thatthe percent of the population reproducing can vary widely, from10 to 98%. Each season was characterized as having delayed,average or advanced ovarian development. In this study we relatethese indices to direct and indirect indicators of spring orannual food availability. The timing of the spring sea ice retreatand the extent of sea ice in the spring (September through November)appear to significantly affect the intensity and timing of reproductionin the population. Intensity of reproduction was highest under"average" conditions, and oöcyte development fastest withconditions of a late retreat and high spring sea ice extent.     

The Human Ecology of World Systems in East Africa: The Impact of the Ivory Trade

The impact on human ecology of the ivory trade entailed direct and indirect effects. First, the reduction or extermination of elephant populations had direct effects on the vegetation patterns over large areas. Second, the economic activities connected with hunting, transport, and trading affected regional systems of exchange and thereby, indirectly through the political economy, settlements, patterns of resource utilization, population parameters, and specialization of production. Ethnohistorical information from the 1800s suggests how coastal goods interacted with regional systems of exchange and environmental exploitation. Although such information cannot be directly projected onto the more distant past, it can be used to establish some possible pathways through which the hunting of elephants and transportation and trade of ivory could have affected the ecology of human resource use.     

大分子拥挤对DNA结构的影响

大分子拥挤(macromolecular crowding effect)代表了细胞内高度拥挤状态,其源于非特异性容积排斥效应,是细胞内与pH、离子强度等同等重要的生理因素。生物大分子介导的拥挤环境对于DNA-DNA、DNA-蛋白质的相互作用以及DNA高级结构、细胞核或核区结构的稳定具有重要作用。在拥挤环境中,大分子总浓度的增加将增强溶质的浓缩倾向,从而降低溶液的自由能。拥挤效应是胞内大分子环境的总体反映,具有高度的缓冲性,保证了胞内反应的稳定进行及细胞功能的正常行使。     

Impact of Climate Variability on Infectious Disease in West Africa

The importance of infectious disease as a determinant (as well as an outcome) of poverty has recently become a prominent argument for international and national investment in the control of infectious disease, as can be seen in the recently articulated United Nations (UN) Millennium Development Goals (MDGs). Climate variability and land use change have an enormous impact on health in West Africa, and may yet undermine the potential for achieving the MDGs, in certain economic-ecological zones. However, their underlying role in determining the burden of disease in the region on a yearly or decadal basis has never been systematically studied. In order to improve our understanding of the future impacts of climate change, it may be more effective to start by investigating the impact of inter-annual climate variability, and short-term shifts in climate (e.g., decadal), on disease transmission dynamics. This information may inform both current and future policy decisions with regard to prediction, prevention, and management of adverse climate-related health outcomes. This article reviews current knowledge of changes in the epidemiology of infectious diseases associated with climate variability in West Africa over the last 40 years. Selected examples are considered from bacterial (meningococcal meningitis), protozoan (malaria), and filarial (onchocerciasis and lymphatic filariasis) infections where spatial and temporal disease patterns have been directly influenced by seasonal, inter-annual, or decadal changes in climate.The views expressed herein are those of the authors and do not necessarily reflect the views of the National Oceanic and Atmospheric Administration (NOAA) or any of its sub-agencies.     

Human Bocavirus Capsid Structure: Insights into the Structural Repertoire of the Parvoviridae

Human bocavirus (HBoV) was recently discovered and classified in the Bocavirus genus (family Parvoviridae, subfamily Parvovirinae) on the basis of genomic similarity to bovine parvovirus and canine minute virus. HBoV has been implicated in respiratory tract infections and gastroenteric disease in children worldwide, yet despite numerous epidemiological reports, there has been limited biochemical and molecular characterization of the virus. Reported here is the three-dimensional structure of recombinant HBoV capsids, assembled from viral protein 2 (VP2), at 7.9-Å resolution as determined by cryo-electron microscopy and image reconstruction. A pseudo-atomic model of HBoV VP2 was derived from sequence alignment analysis and knowledge of the crystal structure of human parvovirus B19 (genus Erythrovirus). Comparison of the HBoV capsid structure to that of parvoviruses from five separate genera demonstrates strong conservation of a β-barrel core domain and an α-helix, from which emanate several loops of various lengths and conformations, yielding a unique surface topology that differs from the three already described for this family. The highly conserved core is consistent with observations for other single-stranded DNA viruses, and variable surface loops have been shown to confer the host-specific tropism and the diverse antigenic properties of this family.Human bocavirus (HBoV), a newly discovered member of the family Parvoviridae, was originally isolated in randomly selected nasopharyngeal aspirates (5). Since this initial discovery, HBoV has also been detected worldwide, predominantly in children under the age of 2 years with respiratory infections, in serum, urine, and fecal samples (40). Symptomatic children commonly exhibit acute diseases of the upper and lower respiratory tracts (7, 36, 44, 56) and, possibly, gastroenteritis (31, 56) though the link to gastroenteritis outbreaks has been questioned (12). It is still unclear if HBoV is the sole etiologic agent of respiratory disease as higher rates of coinfections with other respiratory pathogens such as human rhinovirus and Streptococcus spp. are often observed (4). However, Allander et al. recently reported (4) that HBoV was found in 19% of children with acute wheezing, thereby making it the fourth most common virus, after rhinoviruses, enteroviruses, and respiratory syncytial virus, detected in children exhibiting this symptom. These findings suggest that, at high viral load, HBoV could be an etiologic agent of respiratory tract disease (4). HBoV infection is common in the first few years of life, and clinical research suggests it may follow the primary period for acquisition of human parvovirus B19 (B19) though there is no antigenic cross-reactivity between B19 and HBoV (28, 30). By age 5, most people have circulating antibodies against HBoV, as is also true for other respiratory viruses such as respiratory syncytial virus, rhinoviruses, and human metapneumovirus (17). HBoV has also been identified in adults, with ∼63% of samples tested being seropositive, showing a positive correlation with age and a slight positive bias toward women (14).The Parvoviridae is a family of small, nonenveloped viruses that package a single-stranded DNA (ssDNA) genome of ∼5,000 bases. These viruses are subdivided into two subfamilies: Parvovirinae and Densovirinae (Table ​(Table1).1). The Parvovirinae are further subdivided into five genera, all of whose members infect vertebrates. The Densovirinae (four genera) infect only invertebrates. Phylogenetic analysis places HBoV in the recently classified Bocavirus genus (Table ​(Table1).1). In addition to HBoV, numerous parvoviruses circulate among the human population. Among these are the following: several dependoviruses; adeno-associated virus (AAV) serotypes AAV1 to AAV3, AAV5, and AAV9; the Erythrovirus B19; and the newly discovered human parvovirus genotypes 4 (Parv4) and 5 (Parv5) (23, 27, 50). Of these, only B19 had been implicated in disease until the discovery of HBoV and Parv4, which has been isolated from patients who present symptoms of acute HIV infection (50).

TABLE 1.

Selected properties of representative members of the Parvoviridae

The NMR Structure of Human Obestatin in Membrane-Like Environments: Insights into the Structure-Bioactivity Relationship of Obestatin

The quest for therapeutic applications of obestatin involves, as a first step, the determination of its 3D solution structure and the relationship between this structure and the biological activity of obestatin. On this basis, we have employed a combination of circular dichroism (CD), nuclear magnetic resonance (NMR) spectroscopy, and modeling techniques to determine the solution structure of human obestatin (1). Other analogues, including human non-amidated obestatin (2) and the fragment peptides (6–23)-obestatin (3), (11–23)-obestatin (4), and (16–23)-obestatin (5) have also been scrutinized. These studies have been performed in a micellar environment to mimic the cell membrane (sodium dodecyl sulfate, SDS). Furthermore, structural-activity relationship studies have been performed by assessing the in vitro proliferative capabilities of these peptides in the human retinal pigmented epithelial cell line ARPE-19 (ERK1/2 and Akt phosphorylation, Ki67 expression, and cellular proliferation). Our findings emphasize the importance of both the primary structure (composition and size) and particular segments of the obestatin molecule that posses significant α-helical characteristics. Additionally, details of a species-specific role for obestatin have also been hypothesized by comparing human and mouse obestatins (1 and 6, respectively) at both the structural and bioactivity levels.