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151.
A number of international agreements and commitments emphasize the importance of appropriate monitoring protocols and assessments as prerequisites for sound conservation and management of the world’s forest ecosystems. Mandated periodic surveys, like forest inventories, provide a unique opportunity to identify and properly satisfy natural resource management information needs. Distinctively, there is an increasing need for detecting diversity by means of unambiguous diversity measures. Because all diversity measures are functions of tree species abundances, estimation of tree diversity indices and profiles is inevitably performed by estimating tree species abundances and then estimating indices and profiles as functions of the abundance estimates. This strategy can be readily implemented in the framework of current forest inventory approaches, where tree species abundances are routinely estimated by means of plots placed onto the surveyed area in accordance with probabilistic schemes. The purpose of this paper is to assess the effectiveness of this strategy by reviewing theoretical results from published case studies. Under uniform random sampling (URS), that is when plots are uniformly and independently located on the study region, consistency and asymptotic normality of diversity index estimators follow from standard limit theorems as the sampling effort increases. In addition, variance estimation and bias reduction are achieved using the jackknife method. Despite its theoretical simplicity, URS may lead to uneven coverage of the study region. In order to avoid unbalanced sampling, the use of tessellation stratified sampling (TSS) is suggested. TSS involves covering the study region by a polygonal grid and randomly selecting a plot in each polygon. Under TSS, the diversity index estimators are consistent, asymptotically normal and more precise than those achieved using URS. Variance estimation is possible and there is no need to reduce bias.  相似文献   
152.
Kawasaki disease is a multisystemic vasculitis that can result in coronary artery lesions. It predominantly affects young children and is characterized by prolonged fever, diffuse mucosal inflammation, indurative oedema of the hands and feet, a polymorphous skin rash and non‐suppurative lymphadenopathy. Coronary artery involvement is the most important complication of Kawasaki disease and may cause significant coronary stenosis resulting in ischemic heart disease. The introduction of intravenous immunoglobulin decreases the incidence of coronary artery lesions to less than 5%. The etiopathogenesis of this disease remains unclear. Several lines of evidence suggest that an interplay between a microbial infection and a genetic predisposition could take place in the development of the disease. In this review, we summarize the state of the art of pathogenetic mechanisms of Kawasaki disease underscoring the relevance of haematological features as a novel field of investigation.  相似文献   
153.
Haematophagous insects are frequently carriers of parasitic diseases, including malaria. The mosquito Anopheles gambiae is the major vector of malaria in sub-Saharan Africa and is thus responsible for thousands of deaths daily. Although the role of olfaction in A. gambiae host detection has been demonstrated, little is known about the combinations of ligands and odorant binding proteins (OBPs) that can produce specific odor-related responses in vivo. We identified a ligand, indole, for an A. gambiae odorant binding protein, AgamOBP1, modeled the interaction in silico and confirmed the interaction using biochemical assays. RNAi-mediated gene silencing coupled with electrophysiological analyses confirmed that AgamOBP1 binds indole in A. gambiae and that the antennal receptor cells do not respond to indole in the absence of AgamOBP1. This case represents the first documented instance of a specific A. gambiae OBP–ligand pairing combination, demonstrates the significance of OBPs in odor recognition, and can be expanded to the identification of other ligands for OBPs of Anopheles and other medically important insects.  相似文献   
154.
Human antibody 4E10 targets the highly conserved membrane-proximal external region (MPER) of the HIV-1 transmembrane glycoprotein, gp41, and has extraordinarily broad neutralizing activity. It is considered by many to be a prototype for vaccine development. In this study, we describe four subjects infected with viruses carrying rare MPER polymorphisms associated with resistance to 4E10 neutralization. In one case resistant virus carrying a W680G substitution was transmitted from mother to infant. We used site-directed mutagenesis to demonstrate that the W680G substitution is necessary for conferring the 4E10-resistant phenotype, but that it is not sufficient to transfer the phenotype to a 4E10-sensitive Env. Our third subject carried Envs with a W680R substitution causing variable resistance to 4E10, indicating that residues outside the MPER are required to confer the phenotype. A fourth subject possessed a F673L substitution previously associated with 4E10 resistance. For all three subjects with W680 polymorphisms, we observed additional residues in the MPER that co-varied with position 680 and preserved charged distributions across this region. Our data provide important caveats for vaccine development targeting the MPER. Naturally occurring Env variants described in our study also represent unique tools for probing the structure-function of HIV-1 envelope.  相似文献   
155.
Data acquisition to perform LCA is time and capital consuming. There is already international data about environmental aspects in several processes. This study aims to verify the possibility of adapting international data to Brazilian conditions. Therefore, a Life Cycle Inventory was conducted to compare the use of national and international data for steel used in automobiles. This was done in three steps: objective and scope definition, inventory analysis and interpretation. LCI is a simplification of Life Cycle Assessment (LCA) as impact assessment is not taken into account. Even so, LCI takes into account all life cycle stages of a product, that is, from its extraction through its deposition. In this study, three phases of the life cycle were considered: steel manufacturing, automobile use and disposal. In the case studied, the amount of steel evaluated was 263 kg, which would be possible to be replaced by other materials in a 1,300 kg automobile. Resources and energy consumption, atmospheric emissions and solid residues production were taken into account within the analysis done. Results show that automobile use and materials manufacturing are responsible for the bulk of energy and resources consumption. Solid residues occur mainly in the discard phase, due to the low level of recycling. Several differences were also achieved between national and international data, which implies the need of environmental databases development.  相似文献   
156.
Gafni A  Walter NG 《Biopolymers》2008,89(4):256-261
The Michigan Biophysics Graduate Program (MBGP) was established in 1949, making it one of the first such programs in the world. The intellectual base of the program was significantly broadened in the 1980 when faculty members from a number of other units on campus were invited to join. Currently over forty faculty members from a variety of disciplines participate as mentors for the Ph.D. students enrolled in the MBGP providing our students with rich opportunities for academic learning and research. The MBGP has two main objectives: 1) to provide graduate students with both the intellectual and technical training in modern biophysics, 2) to sensitize our students to the power and unique opportunities of interdisciplinary work and thinking so as to train them to conduct research that crosses the boundaries between the biological and physical sciences. The program offers students opportunities to conduct research in a variety of areas of contemporary biophysics including structural biology, single molecule spectroscopy, spectroscopy and its applications, computational biology, membrane biophysics, neurobiophysics and enzymology. The MBGP offers a balanced curriculum that aims to provide our students with a strong academic base and, at the same time, accommodate their different academic backgrounds. Judging its past performance through the success of its former students, the MBGP has been highly successful, and there is every reason to believe that strong training in the biophysical sciences, as provided by the MBGP, will become even more valuable in the future both in the academic and the industrial settings. in the academic and the industrial settings.  相似文献   
157.
IntroductionThe instrumented-Timed-Up-and-Go test (iTUG) provides detailed information about the following movement patterns: sit-to-walk (siwa), straight walking, turning and walk-to-sit (wasi). We were interested in the relative contributions of respective iTUG sub-phases to specific clinical deficits most relevant for daily life in Parkinson’s disease (PD). More specifically, we investigated which condition–fast speed (FS) or convenient speed (CS)–differentiates best between mild- to moderate-stage PD patients and controls, which parameters of the iTUG sub-phases are significantly different between PD patients and controls, and how the iTUG parameters associate with cognitive parameters (with particular focus on cognitive flexibility and working memory) and Health-Related-Quality of Life (HRQoL).MethodsTwenty-eight PD participants (65.1±7.1 years, H&Y stage 1–3, medication OFF state) and 20 controls (66.1±7.5 years) performed an iTUG (DynaPort®, McRoberts BV, The Netherlands) under CS and FS conditions. The PD Questionnaire 39 (PDQ-39) was employed to assess HRQoL. General cognitive and executive functions were assessed using the Montreal Cognitive Assessment and the Trail Making Test.ResultsThe total iTUG duration and sub-phases durations under FS condition differentiated PD patients slightly better from controls, compared to the CS condition. The following sub-phases were responsible for the observed longer total duration PD patients needed to perform the iTUG: siwa, turn and wasi. None of the iTUG parameters correlated relevantly with general cognitive function. Turning duration and wasi maximum flexion velocity correlated strongest with executive function. Walking back duration correlated strongest with HRQoL.DiscussionThis study confirms that mild- to moderate-stage PD patients need more time to perform the iTUG than controls, and adds the following aspects to current literature: FS may be more powerful than CS to delineate subtle movement deficits in mild- to moderate-stage PD patients; correlation levels of intra-individual siwa and wasi parameters may be interesting surrogate markers for the level of automaticity of performed movements; and sub-phases and kinematic parameters of the iTUG may have the potential to reflect executive functioning and HRQoL aspects of PD patients.  相似文献   
158.
Zusammenfassung Nach einem Überblick über die Formenmannigfaltigkeit der rudimentären Ventralspreite, der Schuppe, der Nektarblätter vonRanunculus, wird an Hand vonRanunculus platanifolius undsceleratus sowieBatrachium trichophyllum versucht, den Bau der hufeisenförmigen und der geschlossenen ring- oder röhrenförmigen Nektarschuppe zu klären, da diese Schuppenformen nicht ohne weiteres aus dem Spreitenbau der an sich peltaten Nektarblätter verständlich sind.Die Untersuchung der Ontogenese und der Bündelversorgung der röhrenförmigen Nektarschuppen vonRanunculus platanifolius undBatrachium trichophyllum erwies sich dabei als nicht sehr aufschlußreich: der vordere Schuppenrand geht aus der Mitte einer basalen Verdickung der Blattanlage hervor, wächst seitlich empor und schließt nach einem hufeisenförmigen Zwischenstadium dann apikal zusammen; die vier Schuppenbündel vonRanunculus platanifolius, die dem Dorsalmedianus und einem Lateralis entspringen, bilden einen ventral offenen Bogen, beiBatrachium trichophyllum sind bloß zwei Bündel vorhanden, Äste des Dorsalmedianus, die aber bereits unterhalb des Nektargewebes endigen; die Orientierung der Schuppenbündel ist bei beiden Arten wegen der zarten Beschaffenheit nicht festzustellen.Die Lösung brachteRanunculus sceleratus, dessen Schuppenform normalerweise zwischen einem elliptischen Wall und einem oben offenen Hufeisen schwankt. Bei ihm wurden nämlich häufig Nektarblätter mit drei hufeisenförmigen Schuppenwällen gefunden, wobei die äußeren Randwülste der seitlichen Schuppen stets in den Spreitenrand übergingen. Zwischenformen zwischen verbildeten Antheren und Nektarblättern zeigten zudem ganz klar, daß diese Wülste selbst Teile des ventralen Spreitenrandes sind: die mit der Dorsalspreite kongenital verwachsene Ventralspreite ist median eingeschnitten und damit zweilappig, wie sie, freilich unverwachsen, ja auch bei verschiedenen Sapindaceen-Kronblättern anzutreffen ist; die basalen Randschleifen des medianen und der seitlichen (zwischen Dorsal- und Ventralspreite gelegenen) Einschnitte sind zu den drei Schuppenwällen verdickt. Da im Normalfall beiRanunculus undBatrachium der ventrale Spreitenrand seitlich in seiner Entwicklung gehemmt ist, bildet sich gewöhnlich nur die Randschleife des Medianeinschnittes zu einer normalen Nektarschuppe aus. Die Abrundung des von echten Randteilen gebildeten Hufeisenbogens zu einem ring- oder röhrenförmigen Gebilde aber erfolgt durch eine zusätzliche Neubildung, die mit dem Bau der Ventralspreite nichts zu tun hat.  相似文献   
159.
Summary The inactivation of phage T4 by nitrous acid (HNO2) is essentially an exponential function of time of treatment. HNO2-inactivated T4 is able to undergo multiplicity reactivation, and genetic markers may be rescued by live phage, however, the extent of both effects is appreciably less than after UV-inactivation. Also, the survival of phenotypic function of the cistronsr II-A andr II-B is lower with HNO2-treatment than with a UV-irradiation of a corresponding number of hits.The reduced effects are quantitatively accounted for by the assumption of lethal hits blocking early steps of infection. These early-step damages amount to approximately 1/6 of the total hit number; it is still unknown whether they occur in DNA or in protein. Some indication for the occurrence in protein comes from the result that the host-killing efficiency of HNO2-inactivated phage is reduced at a similar rate as these early-step damages occur. However, at least 5/6 of the lethal hits are due to chemical changes within the DNA, as can be calculated from the results of multiplicity reactivation, marker rescue, and phenotypic survival of therII-cistrons.

Mit 6 Textabbildungen  相似文献   
160.
The cutaneous manifestations of the male external genitalia are difficult to diagnose. They may be associated with systemic disease (Reiter''s disease, psoriatic arthritis, angiokeratoma corporis diffusum). In dealing with a lesion of this area that does not heal, adequate biopsy is advisable to rule out malignant disease (Bowen''s disease, melanoma, Kaposi''s sarcoma, Paget''s disease, erythroplasia).  相似文献   
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