Integration of DNA into bacterial chromosomes from plasmids without a counter-selection marker.

Most bacteria can only be transformed with circular plasmids, so robust DNA integration methods for these rely upon selection of single-crossover clones followed by counter-selection of double-crossover clones. To overcome the limited availability of heterologous counter-selection markers, here we explore novel DNA integration strategies that do not employ them, and instead exploit (i) activation or inactivation of genes leading to a selectable phenotype, and (ii) asymmetrical regions of homology to control the order of recombination events. We focus here on the industrial biofuel-producing bacterium Clostridium acetobutylicum, which previously lacked robust integration tools, but the approach we have developed is broadly applicable. Large sequences can be delivered in a series of steps, as we demonstrate by inserting the chromosome of phage lambda (minus a region apparently unstable in Escherichia coli in our cloning context) into the chromosome of C. acetobutylicum in three steps. This work should open the way to reliable integration of DNA including large synthetic constructs in diverse microorganisms. © 2011 The Author(s)

The student achievement decline at sixth grade and the practices impacting achievement

A trend in the decline of proficiency levels, as measured by the Iowa Tests of Basic Skills (ITBS), exists at the sixth grade in both Mathematics and Reading Comprehension across the state of Iowa (Adequate Yearly Progress Statistics (2006–2008) [Data File] Des Moines, IA: Iowa Department of Education). This mixed method study focused on the practices impacting student performance between the fifth grade and the sixth grade. Research related to the decline of sixth grade student achievement reveals the possible factors resulting in lower achievement: Grade span configuration, the transition between fifth and sixth grade, adolescent development and middle level practices implemented consistently as possible reasons for the decline in achievement (Hough, 1995 & Alspaugh, 1998). Phase one of this mixed method study, the quantitative phase, examined whether having a grade span configuration of 5–8 versus 6–8 has a relationship to student achievement. A statistical analysis was performed using 58 medium-sized schools configured as 5–8 or 6–8 schools. A t -test was run to see if there was a statistically significant relationship between grade-span configuration and student achievement; those tests reveals no statistically significant relationship between either a 5–8 or a 6–8 configured school and increased student achievement. Phase two of this mixed method study, the qualitative phase, examined the common practices and principles related to stable or increased student achievement between fifth grade and sixth grade. Four schools, two 5–8 configured schools and two 6–8 configured schools participated in this qualitative study. Data from document collection, focus group interviews and classroom observations were triangulated to determine common practices leading to stable or increased achievement scores as measured by the ITBS standardized test. Five common themes and subthemes emerged from the qualitative phase of this study. Named, Pillars of Practice and Strategies for Student Success, these common themes were found in the two schools with stable or increased achievement. The themes and subthemes could provide a tool for analyzing their schools\u27 current practice with a critical eye. Since there is currently limited research done on sixth grade achievement, this study adds to the body of knowledge on this topic. Few studies have moved beyond the relationship between grade-span configuration and achievement levels as this study has done. Identified practices detailed in the Pillars of Practice could assist many schools in analyzing current practice resulting in improved student achievement

Characteristics and outcome of patients with newly diagnosed advanced or metastatic lung cancer admitted to intensive care units (ICUs)

BACKGROUND: Although patients with advanced or metastatic lung cancer have poor prognosis, admission to the ICU for management of life-threatening complications has increased over the years. Patients with newly diagnosed lung cancer appear as good candidates for ICU admission, but more robust information to assist decisions is lacking. The aim of our study was to evaluate the prognosis of newly diagnosed unresectable lung cancer patients. METHODS: A retrospective multicentric study analyzed the outcome of patients admitted to the ICU with a newly diagnosed lung cancer (diagnosis within the month) between 2010 and 2013. RESULTS: Out of the 100 patients, 30 had small cell lung cancer (SCLC) and 70 had non-small cell lung cancer. (Thirty patients had already been treated with oncologic treatments.) Mechanical ventilation (MV) was performed for 81 patients. Seventeen patients received emergency chemotherapy during their ICU stay. ICU, hospital, 3- and 6-month mortality were, respectively, 47, 60, 67 and 71%. Hospital mortality was 60% when invasive MV was used alone, 71% when MV and vasopressors were needed and 83% when MV, vasopressors and hemodialysis were required. In multivariate analysis, hospital mortality was associated with metastatic disease (OR 4.22 [1.4-12.4]; p = 0.008), need for invasive MV (OR 4.20 [1.11-16.2]; p = 0.030), while chemotherapy in ICU was associated with survival (OR 0.23, [0.07-0.81]; p = 0.020). CONCLUSION: This study shows that ICU management can be appropriate for selected newly diagnosed patients with advanced lung cancer, and chemotherapy might improve outcome for patients with SCLC admitted for cancer-related complications. Nevertheless, tumors' characteristics, numbers and types of organ dysfunction should be taken into account in the decisional process before admitting these patients in ICU.Peer reviewe

Improvement in Chronic Hepatocerebral Degeneration Following Liver Transplantation

Chronic progressive hepatocerebral degeneration with spastic paraparesis, dementia, dysarthria, ataxia, tremor, and neuropsychiatric symptoms follows long-standing portal-systemic shunting, is associated with structural changes in the central nervous system, and does not respond to conventional therapy for hepatic encephalopathy. A case of advanced chronic liver disease with severe, progressive hepatocerebral degeneration after 23 yr of portal-systemic shunting is reported in whom there was significant objective improvement in intellectual function and in the chronic neurological signs 3 mo after orthotopic liver transplantation and further improvement 12 mo after transplantation

A study of preplanting herbicides, nitrogen, burning and post-emergence cultivation on the stablishment of Leucaena leucocephala cv. Peru

In a glasshouse trial chlorthal, trifluralin and benfluralin at 8.4, 1.12 and 1.68 kg a.i./ha, respectively, suppressed weed emergence without any detrimental effect on leucaena (L. leucocephala) emergence, but doubling the herbicide rate reduced leucaena emergence. 2,4-D amine at 3.16kg active constituent/ha did not give satisfactory weed suppression and at double this rate suppressed the leucaena emergence

Ground deformation detection of the greater area of Thessaloniki (Northern Greece) using radar interferometry techniques

In the present study SAR interferometric techniques (stacking of conventional interferograms and Permanent Scatterers), using images from satellites ERS-1 and 2, have been applied to the region of Thessaloniki (northern Greece). The period covered by the images is 1992–2000. Both techniques gave good quantitative and qualitative results. The interferometric products were used to study ground surface deformation phenomena that could be related to the local tectonic context, the exploitation of underground water and sediments compaction. <br><br> The city of Thessaloniki shows relatively stable ground conditions. Subsidence in four locations, mainly in the area surrounding the city of Thessaloniki, has been detected and assessed. Two of the sites (Sindos-Kalochori and Langadhas) were already known from previous studies as subsiding areas, using ground base measurements. On the contrary the other two sites in the northern suburbs of Thessaloniki (Oreokastro) and in the south-east (airport area) were unknown as areas of subsidence. A further investigation based on fieldwork is needed in these two areas. Finally, an attempt to interpret the observed deformation, according to the geological regime of the area and its anthropogenic activities, has been carried out

Hepatitis B vaccine boosters: is there a clinical need in high endemicity populations?

The Steering Committee for the Prevention and Control of Infectious Diseases in Asia recently conducted a survey of primary-care physicians in Asia, which revealed that many physicians administer boosters in their clinical practice and that there is considerable variation and uncertainty among physicians regarding this practice. This paper serves as a response to physicians' uncertainties by reviewing the literature regarding the administration of hepatitis B vaccine boosters in high endemicity areas and presenting the Steering Committee's guidelines for booster administration. While there are few data to support a need for routine hepatitis B vaccine boosters as a public health measure, they help to provide reassurance of immunity against breakthrough infection in certain risk groups. In clinical practice, primary-care physicians must exercise their judgment regarding the need for booster vaccination on an individual basis. This paper examines the available literature on the administration and value of hepatitis B vaccine boosters, explores the differences between the public health approach and clinical practice, and provides guidelines for those who use boosters in high endemicity Asian populations. Relevant articles were identified through searches of MEDLINE (1975-2003) and the Cochrane Library, using 'hepatitis B' and 'booster' as primary search terms. Guidelines for those who decide to administer hepatitis B vaccine boosters include: boosting approximately 10-15 years after primary vaccination; boosting rather than not when monitoring of antibody levels is not feasible; boosting immunocompromised patients when the antibody to hepatitis B surface antigen titer falls below 10 mIU/mL; and boosting healthcare workers based on the endemicity of the particular country

Factors Affecting Posterior Capsule Opacification in the Development of Intraocular Lens Materials

Posterior capsule opacification (PCO) is the most common complication arising from the corrective surgery used to treat cataract patients. PCO arises when lens epithelial cells (LEC) residing in the capsular bag post-surgery undergo hyper-proliferation and transdifferentiation into myofibroblasts, migrating from the posterior capsule over the visual axis of the newly implanted intraocular lens (IOL). The developmental pathways underlying PCO are yet to be fully understood and the current literature is contradictory regarding the impact of the recognised risk factors of PCO. The aim of this review is firstly to collate the known biochemical pathways that lead to PCO development, providing an up-to-date chronological overview from surgery to established PCO formation. Secondly, the risk factors of PCO are evaluated, focussing on the impact of IOLs’ properties. Finally, the latest experimental model designs used in PCO research are discussed to demonstrate the ongoing development of clinical PCO models, the efficacy of newly developed IOL technology, and potential therapeutic interventions. This review will contribute to current PCO literature by presenting an updated overview of the known developmental pathways of PCO, an evaluation of the impact of the risk factors underlying its development, and the latest experimental models used to investigate PCO. Furthermore, the review should provide developmental routes for research into the investigation of potential therapeutic interventions and improvements in IOL design in the aid of preventing PCO for new and existing patients