970 research outputs found
Banning Commercial Foresting: What are the Costs?
The Philippines' forest cover has suffered from massive denudation through the years due to uncontrolled and indiscriminate commercial logging. Because of this, calls for a total logging ban had been raised in various fora, including in the legislature where bills that consider the possibility of a ban are being studied. However, the possible economic costs of such ban as espoused in some studies has delayed the passage of these bills. This Policy Notes provides some economic costing based on computations that may help in firming up decisions regarding the proposed ban.forestry sector, environmental issues, environmental management
Concurrent Primary Cardiac Tumors in a High-Risk Patient Presenting With Tamponade.
Primary cardiac tumors are rare, particularly in the elderly population. The patient described in this report presented with symptoms of dyspnea on exertion, leg swelling, and weight gain and was found to have two histologically distinct cardiac masses: atrial myxoma with concurrent aortic fibroelastoma. Given her history of cirrhosis and end-stage renal disease, the patient was a poor surgical candidate but opted for excision of both masses. The patient eventually succumbed to her cirrhosis six weeks after presentation. In this report, we advocate for further research into medical management for the unique presentation of concurrent primary cardiac tumors in high-operative-risk patients, particularly those whose symptoms are mostly due to tamponade
Variational Approach to Hard Sphere Segregation Under Gravity
It is demonstrated that the minimization of the free energy functional for
hard spheres and hard disks yields the result that excited granular materials
under gravity segregate not only in the widely known "Brazil nut" fashion, i.e.
with the larger particles rising to the top, but also in reverse "Brazil nut"
fashion. Specifically, the local density approximation is used to investigate
the crossover between the two types of segregation occurring in the liquid
state, and the results are found to agree qualitatively with previously
published results of simulation and of a simple model based on condensation.Comment: 10 pages, 3 figure
Treatment with lamivudine, zidovudine, or both in hiv-positive patients with 200 to 500 cd4+ cells per cubic millimeter
Background. The reverse-transcriptase inhibitor
lamivudine has in vitro synergy with zidovudine
against the human immunodeficiency virus (HIV). We
studied the activity and safety of lamivudine plus zidovudine
as compared with either drug alone as treatment for
patients with HIV infection, most of whom had not previously
received zidovudine.
Methods. Three hundred sixty-six patients with 200
to 500 CD4+ cells per cubic millimeter who had received
zidovudine for four weeks or less were randomly assigned
to treatment with one of four regimens: 300 mg of
lamivudine every 12 hours; 200 mg of zidovudine every
8 hours; 150 mg of lamivudine every 12 hours plus zidovudine;
or 300 mg of lamivudine every 12 hours plus zidovudine.
The study was double-blind and lasted 24
weeks, with an extension phase for another 28 weeks.
Results. Over the 24-week period, the low-dose and
high-dose regimens combining lamivudine and zidovudine
were associated with greater increases in the
CD4+ cell count (P=0.002 and P=0.015, respectively)
and the percentage of CD4+ cells (P<0.001 for both)
and with greater decreases in plasma levels of HIV type
1 (HIV-1) RNA (P<0.001 for both) than was treatment
with zidovudine alone. Combination therapy was also
more effective than lamivudine alone in lowering plasma
HIV-1 RNA levels and increasing the percentage of
CD4+ cells (P<0.001 for all comparisons), and these advantages
persisted through 52 weeks. Adverse events
were no more frequent with combination therapy than
with zidovudine alone.
Conclusions. In HIV-infected patients with little or no
prior antiretroviral therapy, treatment with a combination
of lamivudine and zidovudine is well tolerated over a oneyear
period and produces more improvement in immunologic
and virologic measures than does treatment with either
agent alone. (N Engl J Med 1995;333:1662-9.
Association of cerebrospinal fluid Aβ42 with A2M gene in cognitively normal subjects
Low cerebrospinal fluid (CSF) Aβ42 levels correlate with increased brain Aβ deposition in Alzheimer’s disease (AD), which suggests a disruption in the degradation and clearance of Aβ from the brain. In addition, APOE ε4 carriers have lower CSF Aβ42 levels than non-carriers. The hypothesis of this investigation was that CSF Aβ42 levels correlate with regulatory region variation in genes that are biologically associated with degradation or clearance of Aβ from the brain. CSF Aβ42 levels were tested for associations with Aβ degradation and clearance genes and APOE ε4. Twenty-four SNPs located within the 5′ and 3′ regions of 12 genes were analyzed. The study sample consisted of 99 AD patients and 168 cognitively normal control subjects. CSF Aβ42 levels were associated with APOE ε4 status in controls but not in AD patientsA2M regulatory region SNPs were also associated with CSF Aβ42 levels in controls, but not in AD patients, even after adjusting for APOE ε4. These results suggest that genetic variation within the A2M gene influences CSF Aβ42 levels
Lifespan extension and the doctrine of double effect
Recent developments in biogerontology—the study of the biology of ageing—suggest that it may eventually be possible to intervene in the human ageing process. This, in turn, offers the prospect of significantly postponing the onset of age-related diseases. The biogerontological project, however, has met with strong resistance, especially by deontologists. They consider the act of intervening in the ageing process impermissible on the grounds that it would (most probably) bring about an extended maximum lifespan—a state of affairs that they deem intrinsically bad. In a bid to convince their deontological opponents of the permissibility of this act, proponents of biogerontology invoke an argument which is grounded in the doctrine of double effect. Surprisingly, their argument, which we refer to as the ‘double effect argument’, has gone unnoticed. This article exposes and critically evaluates this ‘double effect argument’. To this end, we first review a series of excerpts from the ethical debate on biogerontology in order to substantiate the presence of double effect reasoning. Next, we attempt to determine the role that the ‘double effect argument’ is meant to fulfil within this debate. Finally, we assess whether the act of intervening in ageing actually can be justified using double effect reasoning
Mode of administration influences plasma levels of active Centella asiatica compounds in 5xFAD mice while markers of neuroinflammation remain unaltered
IntroductionA water extract of Centella asiatica (L.) Urban [Apiaceae] (CAW) has demonstrated cognitive-enhancing effects in mouse models of Alzheimer’s disease and aging, the magnitude of which is influenced by whether CAW is delivered in the drinking water or the diet. These cognitive benefits are accompanied by improvements in oxidative stress and mitochondrial function in the brain, two pathways related to the neuroinflammatory response. The effect of CAW on neuroinflammation, however, has not been directly studied. Here, we investigated the effect of CAW on neuroinflammation in 5xFAD mice and compared plasma levels of CAW’s active compounds following two modes of CAW administration.MethodsEight-to-nine-month-old male and female 5xFAD mice and their wild-type littermates were administered CAW in their diet or drinking water (0 or 1,000 mg/kg/day) for five weeks. Immunohistochemistry was performed for β-amyloid (Aβ), glial fibrillary acidic protein (GFAP), and Griffonia simplicifolia lectin I (GSL I) in the cortex and hippocampus. Gene expression of inflammatory mediators (IL-6, TNFα, IL-1β, TREM2, AIF1, CX3CR1, CX3CL1, CD36, C3AR1, RAGE, CCR6, CD3E) was measured in the deep grey matter.ResultsCAW decreased cortical Aβ plaque burden in female 5xFAD mice administered CAW in the drinking water but had no effect on Aβ plaques in other treatment groups. CAW did not impact elevated levels of GFAP or GSL I in 5xFAD mice, regardless of sex, brain region, or mode of CAW administration. In the deep grey matter, CAW increased C3AR1 expression in 5xFAD females administered CAW in the drinking water and decreased IL-1β expression in 5xFAD males administered CAW in the diet. CAW had no effect, however, on gene expression levels of any other inflammatory mediator in the deep grey, for either sex or mode of CAW administration. Mice administered CAW in the drinking water versus the diet had significantly higher plasma levels of CAW compounds.DiscussionCAW had little impact on the neuroinflammatory markers selected for evaluation in the present study, suggesting that the cognitive benefits of CAW may not be mediated by an anti-inflammatory effect or that additional molecular markers are needed to fully characterize the effect of CAW on neuroinflammation
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