Effects Of Decline Research Articles

Respuestas del miocardio al estrés biomecánico

Biomechanical stress of the myocardium is the situation resulting from hypoxia, hypertension, and other forms of myocardial injury, that invariably lead to increased demands for cardiac work and/or loss of functional myocardium. As a consequence of biomechanical stress a number of responses develop involving all the myocardial cells, namely cardiomyocytes. As a result some myocardial phenotypic changes develop that are initially compensatory (i.e., hypertrophy) but which may mediate the eventual decline in myocardial function that occurs with the transition from hypertrophy to failure in conditions of persistent stress (i.e., apoptosis and fibrosis). This review focuses on the steps involved in the response of the myocardium to biomechanical stress and highlights the most recent developments in the molecular mechanisms involved in the development of heart failure.

El Niño, water vapor, and the global positioning system

The 1997–1998 El Niño had a profound impact on atmospheric circulation in the tropical Pacific and affected weather patterns world‐wide. Precipitable water estimates from Global Positioning System (GPS) sites in the western tropical Pacific capture the sudden onset of large‐scale subsidence, a phenomenon proposed as a possible mechanism driving the eventual decline of El Niño episodes. The atmospheric drying associated with this anomalous high‐pressure ridge and the turnabout as the warm episode transitions into the subsequent La Niña are clearly visible in the GPS observations.

Reconstitution of human thymic implants is limited by human immunodeficiency virus breakthrough during antiretroviral therapy.

Human immunodeficiency virus type 1 (HIV-1)-infected SCID-hu thymic implants depleted of CD4(+) cells can support renewed thymopoiesis derived from both endogenous and exogenous T-cell progenitors after combination antiretroviral therapy. However, successful production of new thymocytes occurs transiently. Possible explanations for the temporary nature of this thymic reconstitution include cessation of the thymic stromal support function, exhaustion of T-cell progenitors, and viral resurgence. Distinguishing between these processes is important for the development of therapeutic strategies aimed at reconstituting the CD4(+) T-cell compartment in HIV-1 infection. Using an HIV-1 strain engineered to express the murine HSA heat-stable antigen surface marker, we explored the relationship between HIV-1 expression and CD4(+) cell resurgence kinetics in HIV-1-depleted SCID-hu implants following drug therapy. Antiviral therapy significantly suppressed HIV-1 expression in double-positive (DP) CD4/CD8 thymocytes, and the eventual secondary decline of DP thymocytes following therapy was associated with renewed viral expression in this cell subset. Thymocytes derived from exogenous T-cell progenitors induced to differentiate in HIV-1-depleted, drug-treated thymic implants also became infected. These results indicate that in this model, suppression of viral replication occurs transiently and that, in spite of drug therapy, virus resurgence contributes to the transient nature of the renewed thymic function.

Agricultural intensification and the decline of pastoralism: a case study from Kenya

AbstractUsing a case study, this article takes up the issue of the decline of pastoralism in Kenya's arable farming zones. It argues that this process should not be taken as self-evident, with a decline in stockholding seen as consequent simply upon the relative rewards of agriculture, population increase and environmental depletion. On the contrary, such a view ignores the fact that cattle were the first sector of the traditional agro-pastoralist societies of Kenya to become commercialised and, in the process, criminalised. Historically, cattle-raiding heroes soon became feared stock thieves, and it is this process which is essential to understanding the eventual decline of the pastoral sector and also to emerging patterns of inequality. The argument is based upon a longitudinal study of Kuria District in south-west Kenya, with survey data collected from the same homesteads in 1985 and 1995. Both surveys were designed to assess the effects of tobacco growing on emerging patterns of socio-economic stratification. Such a methodology is rare and challenges the interpretations that might be reached solely on the basis of cross-sectional survey data. Despite increasing differentiation of incomes over the ten-year period, there has been no straightforward consolidation of relative wealth and poverty. Rather, there are indications of significant equalising tendencies at work in the local economy. Over the ten years there had been a 50 per cent decrease in cattle ownership. Understanding the dynamics of this situation takes the argument in other directions and towards understanding the effects of commodification on the military wing of the pastoral economy. Agricultural intensification in Kuria has been accompanied by an upsurge in cattle raiding and it is this factor more than any other which has led to the decline of stock, as people divest themselves of cattle to forestall the depredations of raiders. At the same time, attitudes to the raiders themselves have hardened and evidence suggests that it is raiding families—rather than, say, the poor as such—who find it expedient to migrate and in the process sell their land, allowing some consolidation of land holdings by other members of the community.

Technological Innovation and the Rise and Fall of Urban Mass Transit

This article departs from the usual discussion of the role of urban transit in effecting spatial change and looks instead at how public pol - icy and the conflicting demands of various constituencies contributed to the demise of the urban mass transit industry. 1 Five constituent groups affected urban transit's evolution and eventual decline: transit company employees, business interests, politicians, investors, and, of course, riders. Each of these groups placed its own set of demands upon the transit industry—demands that conflicted and competed with one another. It was this conflict, and not the advent of the private automobile, that resulted in transit's demise.

Examining creative performance over time using hierarchical linear modeling: An illustration using film directors

Longitudinal performance of 73 film directors are examined using hierarchical linear modeling (HLM). The HLM analyses model intraindividual performance trajectories (i.e., performance change over time) and interindividual differences in the trajectory parameters (i.e., initial status and rate of change in performance). Results reveal that as a group, directors' performance over careers, measured by critics' ratings, can be described using a quadratic trajectory with an increase in ratings following the initial film, followed by an eventual decline in ratings in later films. However, at the intraindividual level, directors differ in their initial status as well as rate of linear change, and some directors follow an accelerating or decelerating performance pattern. These interindividual differences in initial status, direction of change, and rate of change are related to the mean number of films per year directed by the individual. Implications and future research challenges for modeling longitudinal creative performance with HLM are discussed.

The demographic implications of economic growth in the Isle of Man.

The Isle of Man is a classic case study of the relationship between economic and demographic change as well as an example of a country in which optimum population is central to the creation of government policy. 33 miles long and 13 miles wide with a 1993 resident population of slightly more than 70000 the Isle of Man is situated in the Irish Sea between Britain and Ireland. Population density on the island is officially 316 people per sq. mile but the range of hills which stretches across the island limits the area of habitable land. There are consistently 100-200 more deaths than births per annum on the island. The Isle of Man is a British Crown Dependency but not a part of the UK locally determining its social policies. Economic history and demographic change are reviewed from the 1700s with focus upon population growth through the eventual population decline to 64282 in the 1986 interim census. That decline demonstrated the need for a new package of measures to avoid the cyclical stagnation of earlier decades to regenerate the Manx economy through the attraction of new businesses and to counteract the natural tendency toward a declining population level. Optimum population and the New Residents Campaign are discussed. The Manx government continues to pursue demographic growth.

Bright access: Midwestern literary societies, with a particular look at a university for the “farmer and the poor”;

The history of literary societies in academia has been little studied. The few discussions of the societies have centered primarily around eastern universities and have marked the societies' decline as coming in the mid-to-late 1800s. However, the literary societies survived at many Midwestern colleges, both public and private, for several decades into the twentieth century. The societies embody rhetoric-in-practice and are interesting in terms of their social structure, their intellectual activities, and what they tell us about the position of rhetoric in the late nineteenth and early twentieth centuries. Their eventual decline is brought about by a number of forces, some predictable and some not. Academic literary societies, which existed in strength in the Midwest from about 1830 to 1920, centered around the writing and performance of essays, debates, orations, and sometimes poetry. Over time, some of the groups expanded their activities into performances of music and dramas, with these elements sometimes overtaking the rhetorical aspects. As has been noted elsewhere, the societies declined with the coming of fraternities and sororities, the blossoming of disciplinary clubs, the general lack of interest in rhetoric, and the influx of students seeking a public education. Other less-examined factors include the extent of institutional support, the strength of rhetoric in the

Evolutionary trends of industry variables

The paper offers empirical evidence on the evolutionary trends of industry variables. It investigates the time path of patents, product price and quantity, and number of firms from the first introduction of a product to maturity of the market. The paper extends earlier work by Gort and Klepper by expanding the data on products through 1991, and augmenting it with new products and new data sources. The reexamination of the aging patterns reveal the Gort and Klepper results to be robust. The time trends follow the expected patterns with remarkable consistency and are strongly significant for most products. New evidence on patenting activity reveal an eventual decline in technological activity over the later years of the product market life-cycle.

SURFACE TRANSPORT HISTORY IN THE UK:ANALYSIS AND PROJECTIONS.

A comparative analysis is given of the history of the three main forms of surface transport in the UK: the canal, railway, and car/road systems. There are common features in each of these systems, in terms of growth, technology utilization, and eventual decline. The analysis suggests that the era of dominance of surface transport by the automobile is now drawing to an end, and that it is reasonable to expect a new form of transport to come into being, involving new vehicles matched to a new infrastructure, and designed to meet new requirements, notably the issues of sustainability. (A)

Competitiveness in the clothing industry: The economics of fashion in UK womenswear, 1880–1950

Most recent prescriptions for firm development in the garment industry have focused on methods of reducing labour costs, with less emphasis placed on targeting high margin niches. This paper examines how the early ready‐made womenswear industry in the UK moved from a wage‐cost containment strategy before the First World War to exploiting fashion‐sensitive demand in the inter‐war period. The economics of fashion‐sensitive demand meant that the most efficient structure for the industry was to have many small producers, specialised in sub‐processes, and all closely located. However, contemporaries failed to understand the efficiency properties of the ‘industrial district’ type of local economy which emerged in London's East End in the first half of this century, a failure which eventually contributed to the dispersion of industrial activities and to the eventual decline of the industry.

Microglial Expression of MHC Class II Increases in Normal Aging of Nonhuman Primates

The search for factors that influence age-related behavioral and cognitive slowing is ongoing. Because microglia are involved in many neurological disorders, they may also contribute to changes in normal aging. To assess increases in microglial activity, we used an antibody against MHC class II to label microglia in three groups of brains from female Macaca nemestrina: juvenile (2–5 years), young adult (5–11 years), and mature (11–19 years). Image analysis was completed on four white matter and three gray matter regions in a single coronal plane. Microglial expression of MHC class II increased with age, and was highest in the white matter regions of the mature, or middle-aged, monkeys. The higher expression of this antigen may indicate that the cells will more easily respond to stimulation. Their location in the white matter suggest that they may influence myelin loss and the eventual cognitive decline in aged human and nonhuman primates.

Fort Meade, 1849-1850 (review)

book reviews159 Cattle had grazed in Florida since the Spanish period and well-heeled ranchers were in place by the time of the war. As a removed and presumably safe outpost, the state was a natural source of beef. The export of cattle rivaled in importance that of salt. The Army of Tennessee was a major beneficiary. Yet, with beef, as with much else in the "rebel storehouse," expectations were unfulfilled . Some ranchers balked at selling beeves to the Confederate government, and commissary officials were sometines inefficient. In the meantime, as other army of Confederate beef acquisitions were shut off by advancing Federal armies, Florida beeves took on increased importance. Union troops targeted cattle just as surely as they did salt works, and fewer and leaner cattle was the reality by 1864. "As in the past," Taylor writes, "too much was expected from the Florida peninsula when plans were being formulated to provision the faltering South and its gray warriors" (126). Admittedly, the activities ofcommissary and quartermaster officials does not promise inherent drama and riveting reading. Even so, some might hope for a more lively account ofthe subject, and a greaterfocus on individuals as providers would help.The vignette ofJacob Summerlin, a colorful cattleman who furnished beeves to the Confederacy, is fleshed out well. But that is the exception.A more human dimension could only add flavor and readability. A variety of sources have been consulted, but little research has apparently been done at the National Archives, where a close look at the record collections seems appropriate. These objections do not unduly detract from the contribution that has been made. The Southern economy, as with the homefront generally, has received less attention than is warranted. This book may inspire similar treatments in other states or regions. What was particularly indigenous and valuable to the Confederacy elsewhere? Failures regarding logistical supply may add to the multifaceted explanation for the Confederacy's defeat. At least in Florida, production/supply might best be described as an extremely qualified success. Most fundamentally, the author argues that the state could not be the bottomless granary or the limitless provider that some envisioned. Even so, he notes that scholars have neglected "the extent to which Florida contributed the bounty of its lands to the rebel governments" (67). Taylor has righted that neglect. William Warren Rogers, Jr. Gainesville College Fort Meade, 1849-1850. By Canter Brown. (Tuscaloosa: University of Alabama Press, 1995. Pp. 232. $19.95.) In 199 1, Canter Brown published Florida's Peace River Frontier, a wellreceived study detailing the settlement ofthe southern peninsula during the nineteenth century. Brown's current work focuses specifically on Fort Meade, described by the author as the "oldest town in interior south Florida" (xi). In just over 150 pages of text he outlines the founding of the town, its role during the i6oCIVIL war history Third Seminole and Civil Wars, and its postwar development and eventual decline. The southeastern frontier, Brown contends, has been relatively neglected , as have studies ofcommunities that failed to prosper after the frontier's close. In this regard Fort Meade offers a contrasting view to examples of better-known frontier settlements. Lt. George Gordon Meade established an army post along Florida's Peace River in 1849. Officers later stationed there included A. P. Hill and Thomas J. Jackson. Fort Meade quartered troops and protected settlers during the Third Seminole War and several engagements took place nearby. The war's close brought more white settlement, and by i860 a profitable cattle industry had begun to develop. Fort Meade's inhabitants suffered severe hardships during the CivilWar. The town volunteered its share of men to the Confederacy, but the population included a sizable percentage of Unionists as well. Many Florida cattlemen, Brown argues, hoped to keep their herds intact to take advantage of postwar profits and thus held strong allegiances to neither side. Early in 1864 Federal troops occupied Fort Myers, on the Caloosahatchee River south of Fort Meade. Over the next year southwest Florida was the scene of small-scale, yet bitter fighting, with Union troops attempting to disrupt the supply ofcattle being sent northward from Florida ranges. Significant numbers of Unionists journeyed to Fort Myers...

The Influence of Chaotropic Reagents on Neuronal Nitric Oxide Synthase and Its Flavoprotein Module. Urea and Guanidine Hydrochloride Stimulate NADPH–Cytochrome c Reductase Activity of Both Proteins

Changes in flavin and protein fluorescence of neuronal nitric oxide synthase (nNOS) and its flavoprotein module were studied in the presence of urea and compared with those previously reported for cytochrome P450 reductase (CPR) [R. Narayanasami, P.M. Horowitz, and B.S.S. Masters (1995)Arch. Biochem. Biophys.316, 267–274]. As in the case of CPR, FMN was relatively loosely bound to nNOS and the flavoprotein module, but FAD remained bound at concentrations of up to 2murea. Protein fluorescence increased progressively with increasing urea concentration, but could not be correlated with changes in flavin binding. NADPH–cytochrome c reductase activity of both nNOS and the flavoprotein module, but not that of CPR, was stimulated at early time points by both urea and guanidine hydrochloride (GnHCl), with levels of initial activity returning to baseline values within 60 min after addition of the chaotropic agent. Thus, at 3–4murea, enhancements of reductase activities of 20- and 5-fold with nNOS and the flavoprotein module, respectively, were obtained. Comparable enhancements of 12- and 6- to 7-fold, respectively, were obtained with calmodulin (CaM)/CaCl2and 0.5mGnHCl. Thus, the effects of urea and GnHCl mimicked the stimulating effects of CaM. Separate preincubations of nNOS and cytochrome c with urea or GnHCl prior to initiation of the reductase assay showed that sensitivity to chaotropic agent under these conditions was a property of nNOS and not of cytochrome c. Moreover, when the nonprotein electron acceptor 2,6-dichlorophenolindophenol was employed in place of cytochrome c, comparable stimulation of reductase activity was observed in the presence of either urea or GnHCl. Fluorescence of 4,4′-dianilino-1,1′-binaphthyl-5,5′-disulfate in the presence of either nNOS or the flavoprotein module was increased optimally between 3 and 4murea, consistent with simultaneous exposure of hydrophobic regions of both proteins to solvent and optimization of reductase activity. FMN release from nNOS, but not from the flavoprotein module, was enhanced by CaM. Addition of FMN or FMN + FAD to nNOS, in the presence or absence of urea, brought about a doubling of initial cytochrome c reductase activity, but did not prevent the eventual decline in activity to basal levels. These data are consistent with conformational changes which favor increased electron transfer similar to that achieved with nNOS in the presence of CaM.

Eosinophils and eosinophil-associated cytokines in allergic inflammation.

Eosinophils are major effector cells in allergic tissue reactions. Their capacity to synthesize and store cytokines, particularly Th2-type cytokines, which may have autocrine effects such as increased cell survival in tissues, is of particular current interest. We have shown that eosinophils infiltrating the site of human cutaneous late-phase reactions (LPR) express mRNA and protein product for IL-4 and IL-5. Stimulation of peripheral blood eosinophils in vitro with either IgG or sIgA produces time-dependent induction of IL-4 and IL-5 transcription, indicating that mature cells may undergo local cytokine synthesis. We also demonstrated that bronchial biopsies from patients with both atopic and non-atopic (intrinsic) asthma express IL-4 and IL-5 mRNA which mainly co-localized to T cells, although clear hybridization signals were also obtained with eosinophils and mast cells. On the other hand, immunoreactivity for the corresponding protein was detectable predominantly in eosinophils and mast cells; a finding believed to reflect granule storage of cytokines. We also studied the resolution of the cutaneous LPR. Apoptosis of eosinophils persisted slightly longer than neutrophils in the tissues. The eventual decline in both neutrophil and eosinophil numbers followed on from the peak of the LPR. This was associated with terminal-deoxynucteotidyl-transferase-mediated nick and labelling positive (TUNEL+) (apoptotic) cells with the subsequent removal of apoptotic neutrophils and eosinophils by tissue macrophages. Thus, IL-4 and IL-5 production by eosinophils may amplify local allergic inflammatory responses and, in the case of IL-5, may prolong local tissue survival. However, in the allergen-induced LPR, inflammation rapidly resolves, possibly through the initiation of programmed cell death and phagocytosis of apoptotic cells by macrophages.

Climate change, tree species distributions and forest dynamics: A case study in the mixed conifer/northern hardwoods zone of northern Europe

Three bioclimate variables (growing degree days after budburst, temperature of the coldest month and a moisture index) are used in a model (STASH) to predict potential range limits of north European tree species. CO2-induced climate warming scenarios cause major changes in these limits. The dominant conifers of the mixed conifer/northern hardwoods zone, Picea abies and Pinus sylvestris, retreat from the south and west while Fagus sylvatica and other temperate hardwoods spread to the north. A gap model (FORSKA 2) is used to simulate the associated transient responses of a forest reserve within this zone. In both dry Pinus- and moist Picea- dominated forest communities, Picea continues to increase while Pinus sooner or later declines. These changes are continuing successional (non-climatic) responses to the cessation of disturbance 150 years ago. Climate warming speeds up the succession, and allows Fagus to establish and increase. The eventual decline of Picea however is delayed due to the persistence of old-growth stands. Picea forests subject to continuing disturbance show a more rapid shift to dominance by Fagus and other temperate hardwoods. Delayed immigration of new species, including Fagus, would favour earlysuccessional species such as Betula pendula and Quercus spp. in a forest with reduced biomass and diversity. The results emphasise the complex and sometimes counter-intuitive nature of transient responses, and the importance of considering disturbance history and potential migration rates when predicting the impacts of rapid climate change on forests.

Pilot-scale harvest of recombinant yeast employing microfiltration: a case study

In order to develop a cost-effective recovery process for an intracellular product, crossflow microfiltration was studied for the harvest of a recombinant yeast under severe time constraint. It was required to process yeast broth in a short period of time to minimize the risk for product degradation. Preliminary microfiltration studies employing flat sheet membranes showed high throughout with initial fluxes on the order of water fluxes (> 1000 LMH, regime I, $ ̌ 2 min ), followed by a rapid decay towards a low pseudo-steady state flux (20 LMH, regime II, > 2 min). Exploitation of these high fluxes and control of their eventual decline were crucial in establishing a rapid crossflow filtration process. The effect of several parameters, such as initial cell concentration, shear rate, transmembrane pressure, membrane pore size and medium composition on filtration performance were investigated to better understand the flux decline mechanisms. We found that the major contributor to flux decay was reversible fouling by the cake formation on the membrane surface. Within the operating boundaries of our microfiltration system, large-pore membrane (0.65 μm) was much more desirable for harvesting our yeast (10 μ size) without cell leakage than smaller pore ones (0.22 μm and 0.45 μm). Among adjustable operating parameters, feed flow rate (i.e., shear rate) exerted significant impact on average flux, whereas manipulation of transmembrane pressure afforded little improvement. Although initial cell concentration affected adversely the permeation rates, growth medium components, especially soy-peptone, was deemed pivotal in determining the characteristics of cell cake, thus controlling yeast microfiltration.

Electrocardiographic diagnosis of reperfusion during thrombolytic therapy in acute myocardial infarction

Continuous 12-lead electrocardiographic monitoring was performed in 61 patients receiving thrombolytic therapy for an acute myocardial infarction. Coronary angiography within 90 minutes revealed a patent vessel (Thrombolysis in Myocardial Infarction [TIMI] trial 2 or 3) in 44 patients. Early signs of reperfusion were ST-segment normalization (likelihood ratio 16.0), development of terminal T-wave inversion (likelihood ratio 10.6), accelerated idioventricular rhythm (likelihood ratio 6.0), and a twofold increase in ventricular premature complexes (likelihood ratio 2.5). Relief of chest pain after 60 minutes was reported by 96%. During reperfusion of the infarct-related vessel, an increase in ST-segment deviation was recorded in 61% of the patients, whereas 69% had an increase in chest pain preceding the eventual decline.

Spinal function monitoring by evoked spinal cord potentials in aortic aneurysm surgery

Evoked spinal cord potentials (ESCPs) were monitored in 12 patients who underwent repair of thoracoabdominal aortic aneurysm with a high risk of spinal ischemia. A pair of bipolar catheter electrodes were introduced into the epidural space, one at the level of the C5-T2 vertebrae and the other at the level of T11-L2. Conductive mixed ESCP in seven patients, conductive sensory ESCP in one patient, and segmental descending ESCP in three patients were observed by applying a rectangular electric current to one of each pair of epidural electrodes and recording through the other. Segmental ESCP in response to posterior tibial nerve stimulation was observed in one patient. Following aortic cross-clamping, the I wave of conductive mixed ESCPs gradually decreased in amplitude with latency prolongation in five of the seven patients and disappeared in one of these five; transient augmentation of amplitude was observed before eventual decline in four of these five patients. The N wave of segmental descending ESCP subsequently flattened in two of the three patients and the N1 wave of segmental ESCP in the one patient. Three of the four patients in whom the ESCPs disappeared during aorta clamping recovered the ESCPs after declamping and showed no neurological disorders postoperatively. Intraoperative ESCP monitoring appears to be useful to detect spinal cord ischemia in the early stage and to alert surgeons and anesthesiologists so that timely resuscitative steps can be taken.

Detection of Potato Spindle Tuber Viroid in Avocado Growing in Peru

Potato spindle tuber viroid (PSTVd) was detected in avocado trees growing at several locations in Peru by using nucleic acid spot hybridization assays. A viroidlike nucleic acid with a mobility similar to that of PSTVd was also found by return polyacrylamide gel electrophoresis analysis of RNA extracted from several trees, and a mild strain of PSTVd was recovered from Nicandra physalodes inoculated with leaf sap from affected avocados. Sequence analysis of cDNAs obtained using the polymerase chain reaction with primers to PSTVd indicated the presence of three different sequence variants of PSTVd in the avocado trees. The PSTVd infections were often latent, but some trees coinfected with avocado sunblotch viroid showed symptoms that included bunchiness of the inflorescence, decrease in both fruit size and number, and eventual decline and death. This is the first report of the isolation of PSTVd from a natural host other than potato