A detailed investigation of geomorphological evidence of paleoshorelines and exposed stratigraphic sections of lake deposits, combined with a chronology based on radiocarbon dated charcoal and
...in-situ
14C dating of wave polished bedrock, provide important new constraints on lake level changes of Lake Bosumtwi, Ghana. Thick sequences of laminated silts, alternating with transgressive sands and deltaic gravels, attest to a long history of climatically controlled lake level variations. The post-glacial rise in lake level began sometime after 16.3 ka, reached stable levels first at 14.5
±
0.6 ka and then rose again after ca. 14.3 ka. A significant lake level regression spanned the interval from 12.6
±
0.3 to 11.6
±
0.5 ka, synchronous with the Younger Dryas. Deep lake conditions were reestablished after ca. 11 ka, at which time the lake overtopped the crater. Overflow continued until 8.8
±
0.5 ka, when another significant but short-lived regression occurred. Deep, but probably not overflowing conditions were again reestablished by >
7.2
±
0.3 ka and continued until around 3.2
±
0.1 ka, when lake level dropped precipitously. Multicentury late Holocene highstands occurred at 2.2
±
0.1 and 1.7
±
0.2 ka, although these were significantly lower than those registered in the late glacial and early Holocene. The timing of late glacial events is similar to those recorded elsewhere in Africa and the higher latitudes, and likely reflects the dominant control of high latitude northern hemisphere conditions on the African tropics during the times of large northern hemisphere ice sheets. Mid- to late-Holocene variations appear to be less coupled with changes across Africa and elsewhere, suggesting that regional forcing may be more important during warmer periods.
Remaking the Global Economy offers a state -of-the-art survey of geographical perspectives on the restructuring and reorganization of the global economy. With contributions from leading figures in ...the globalization debate, the book explores the latest thinking and research, as well as the enduring controversies, across a range of interrelated issues.
Techniques for the development of mathematical models in the area of predictive microbiology have greatly improved recently, allowing better and more accurate descriptions of microbial responses to ...particular environmental conditions, thus enabling predictions of those responses to be made with greater confidence. Recognising the potential value of applying these techniques in the food industry, the Ministry of Agriculture, Fisheries and Food (MAFF) initiated a nationally coordinated five-year programme of research into the growth and survival of microorganisms in foods, with the aim of developing a computerised Predictive Microbiology Database in the UK. This initiative has resulted in the systematic generation of data, through protocols which ensure consistency of methodology, so that data in the database are truly comparable and compatible, and lead to reliable predictive models. The approaches taken by scientists involved in this programme are described and the various stages in the development of mathematical models summarized. It is hoped that this initiative and others being developed in the USA, Australia, Canada and other countries, will encourage a more integrated approach to food safety which will influence all stages of food production and, eventually, result in the development of an International Predictive Microbiology Database.
Nod factors secreted by Rhizobium leguminosarum bv. viciae induce root hair deformation, involving a reinitiation of tip growth, and the formation of nodule primordia in Vicia sativa (vetch). ...Ethylene is a potent inhibitor of cortical cell division, an effect that can be counteracted by applying silver ions (Ag+) or aminoethoxy-vinylglycine (AVG). In contrast to the inhibitory effect on cortical cell division, ethylene promotes the formation of root hairs (which involves tip growth) in the root epidermis of Arabidopsis. We investigate the possible paradox concerning the action of ethylene, putatively promoting Nod factor induced tip growth whilst, at the same time, inhibiting cortical cell division. We show, by using the ethylene inhibitors AVG and Ag+, that ethylene has no role in the reinitiation of root hair tip growth induced by Nod factors (root hair deformation) in vetch. However, root hair formation is controlled, at least in part, by ethylene. Furthermore, we show that ACC oxidase, which catalizes the last step in ethylene biosynthesis, is expressed in the cell layers opposite the phloem in that part of the root where nodule primordia are induced upon inoculation with Rhizobium. Therefore, we test whether endogenously produced ethylene provides positional information controlling the site where nodule primordia are formed by determining the position of nodules formed on pea roots grown in the presence of AVG or Ag+.
Genetic variation in the cholinergic muscarinic-2 (M sub(2)) receptor gene (CHRM2) has been associated with the risk for developing depression. We previously reported that M sub(2)-receptor ...distribution volume (V sub(T)) was reduced in depressed subjects with bipolar disorder (BD) relative to depressed subjects with major depressive disorder (MDD) and healthy controls (HCs). In this study, we investigated the effects of six single-nucleotide polymorphisms (SNPs) for CHRM2 on M sub(2)-receptor binding to test the hypotheses that genetic variation in CHRM2 influences M sub(2)-receptor binding and that a CHRM2 polymorphism underlies the deficits in M sub(2)-receptor V sub(T) observed in BD. The M sub(2)-receptor V sub(T) was measured using positron emission tomography and super(18)FFP-TZTP in unmedicated, depressed subjects with BD (n=16) or MDD (n=24) and HCs (n=25), and the effect of genotype on V sub(T) was assessed. In the controls, one SNP (with identifier rs324650, in which the ancestral allele adenine (A) is replaced with one or two copies of thymine (T), showed a significant allelic effect on V sub(T) in the pregenual and subgenual anterior cingulate cortices in the direction AA<AT<TT. In contrast, in BD subjects with the TT genotype, V sub(T) was significantly lower than in BD subjects with the AT genotype in these regions. The BD subjects homozygous for the T -allele also showed markedly lower V sub(T) (by 27 to 37% across regions) than HCs of the same genotype. Post hoc analyses suggested that T homozygosity was associated with a more severe illness course, as manifested by lower socioeconomic function, poorer spatial recognition memory and a greater likelihood of having attempted suicide. These data represent novel preliminary evidence that reduced M sub(2)-receptor V sub(T) in BD is associated with genetic variation within CHRM2. The differential impact of the M sub(2)-receptor polymorphism at rs324650 in the BD and HC samples suggests interactive effects with an unidentified vulnerability factor for BD.
Current lung cancer staging and prognosis methods are based on imaging methods, which may not be sensitive enough for early and accurate detection of metastasis. This study aims to validate the use ...of a panel of markers for circulating cancer cell detection to improve the accuracy of cancer staging, prognosis, and as a rapid assessment of therapeutic response.
We analyzed the National Cancer Institute-Cancer Genome Anatomy Project database to identify potential marker genes for the detection of circulating cancer cells in peripheral blood. Nested real-time quantitative PCR and a scoring method using cancer cell load Lc were employed to correlate the amount of circulating cancer cells with clinical outcomes in 54 non-small cell lung cancer (NSCLC) patients. The Kaplan-Meier method was employed for analysis of prognostic variables.
A panel of four marker genes was identified and experimentally validated. With these marker genes, we achieved an overall positive detection rate of 72% for circulating cancer cells in the peripheral blood of NSCLC patients. Patients who had higher Lc values had worse outcomes and shorter survival times. Patients with poor therapeutic response were revealed by positive detection of circulating cancer cells after therapy. The results correlated well with the patients' survival time.
Circulating cancer cell detection by a panel of markers and the Lc scoring method can supplement the current tumor, node, metastasis staging method for improved prognosis and for rapid assessment of therapeutic response. Together, they may facilitate the design of better therapeutic strategies for the treatment of NSCLC patients.
A retrospective, observational cohort study was conducted to describe the incidence, clinical and microbiological findings and to evaluate risk factors for treatment failure associated with ...prosthetic joint infections (PJIs). We retrospectively reviewed the medical records of all patients undergoing total knee or total hip prosthesis implantation in our institution between 1994 and 2008. Our institution is a 1950-bed tertiary care university hospital and referral centre. A total of 93 patients with PJIs was identified although only 68 patients had undergone prosthesis implantation at our hospital. The overall infection rate was 0.63%. The most common organisms isolated were Gram positive (76.5%), including meticillin-resistant staphylococci. Two-stage arthroplasty was performed in 48 (51.6%) patients, and debridement and retention of the prosthesis in 34 (36.5%) patients. When 43 patients followed up for more than two years after treatment were included in treatment outcome analysis, the overall treatment failure rate was 41.8% (18/43). Staphylococcus aureus infection was the only clinical variable associated with treatment failure (odds ratio: 11.9; 95% confidence interval: 1.07-133.9; P=0.044), after adjustment for the other variables. In conclusion, S. aureus was the most common pathogen isolated in patients with PJI, and an independent risk factor for treatment failure in patients with PJI.
Genetic variation in the cholinergic-muscarinic2 (M2) receptor gene (CHRM2) has been associated with the risk for developing depression. We previously reported that M2-receptor distribution volume ...(VT) was reduced in depressed subjects with bipolar disorder (BD) relative to depressed subjects with major depressive disorder (MDD) and healthy controls (1). In the current study we investigated the effects of six single nucleotide polymorphisms (SNP) for CHRM2 on M2-receptor binding to test the hypotheses that genetic variation in CHRM2 influences M2-receptor binding and that a CHRM2 polymorphism underlies the deficits in M2-receptor VT observed in BD. The M2-receptor VT was measured using PET and 18FFP-TZTP in unmedicated, depressed subjects with BD (n=16) or MDD (n=24) and healthy controls (n=25), and the effect of genotype on VT was assessed. In the controls one SNP (with identifier rs324650, in which the ancestral allele adenine (A) is replaced with one or two copies of thymine (T), showed a significant allelic effect on VT in the pregenual and subgenual anterior cingulate cortices in the direction AA
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