The impact of microbial metabolism on marine dissolved organic matter

Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Annual Reviews for personal use, not for redistribution. The definitive version was published in Annual Review of Marine Science 3 (2011): 567-599, doi:10.1146/annurev-marine-120308-081003.Microbes mediate global biogeochemical cycles through their metabolism, and all metabolic processes begin with the interaction between the microbial cell wall or membrane and the external environment. For all heterotrophs and many autotrophs, critical growth substrates and factors are present within the dilute and heterogeneous mixture of compounds that constitutes dissolved organic matter (DOM). In short, the microbe--molecule interaction is one of the fundamental reactions within the global carbon cycle. Here, I summarize recent findings from studies that examine DOM--microbe interactions from either the DOM perspective (organic geochemistry) or the microbe perspective (microbial ecology). Gaps in our knowledge are highlighted and future integrative research directions are proposed.My research has been funded through the National Science Foundation, the Gordon and Betty Moore Foundation, and Woods Hole Oceanographic Institution internal resources

Gender Disparities in Authorships and Citations in Transplantation Research

Background: Over the past decades, there has been a rapid change in the gender ratio of medical doctors, whereas gender differences in academia remain apparent. In transplantation research, a field already understaffed with female doctors and researchers, there is little published data on the development in proportion, citations, and funding of female researchers over the past years. Methods: To evaluate the academic impact of female doctors in transplantation research, we conducted a bibliometric analysis (01 January 1999 to 31 December 2018) of high-impact scientific publications, subsequent citations, and funding in this field. Web of Science data was used in combination with software R-Package "Gender," to predict gender by first names. Results: For this study, 15 498 (36.2% female; 63.8% male) first and 13 345 (30.2% female; 69.8% male) last author gender matches were identified. An increase in the percentage of female first and last authors is seen in the period 1999-2018, with clear differences between countries (55.1% female authors in The Netherlands versus 13.1% in Japan, for example). When stratifying publications based on the number of citations, a decline was seen in the percentage of female authors, from 34.6%-30.7% in the first group (≤10 citations) to 20.8%-23.2% in the fifth group (>200 citations), for first (P < 0.001) and last (P = 0.014) authors, respectively. From all first author name-gender matches, 6574 (41.6% female; 58.4% male, P < 0.001) publications reported external funding, with 823 (35.5% female; 64.5% male, P = 0.701) reported funding by pharmaceutical companies and 1266 (36.6% female; 63.4% male, P < 0.001) reporting funding by the National Institutes of Health. Conclusions: This is the first analysis of gender bias in scientific publications, subsequent citations, and funding in transplantation research. We show ongoing differences between male and female authors in citation rates and rewarded funding in this field. This requires an active approach to increase female representation in research reporting and funding rewarding

The Effect of Frailty on Outcome After Vascular Surgery

OBJECTIVES: Frailty is a state of increased vulnerability and is a stronger predictor for post-operative outcome than age alone. The aim of this study was to determine whether frailty is associated with adverse 30 day outcome in vascular surgery patients. METHODS: This was a prospective cohort study. All electively operated vascular surgery patients between March 2010 and October 2017 (n = 1201), aged ≥ 60 years were evaluated prospectively. Exclusion criteria were arteriovenous access surgery, percutaneous interventions and minor amputations, resulting in 825 patients for further analysis whereas 195 had incomplete data on Groningen Frailty Indicator (GFI) and were excluded. Frailty was measured using the GFI, a screening tool covering 16 items in the domains of functioning. Patients with a total score of ≥4 were classified as frail. The primary outcome parameter was 30 day morbidity (based on the Comprehensive Complication Index). Secondary outcome measures were 30 day mortality, hospital readmission, and type of care facility after discharge. Outcomes were adjusted for sex, body mass index, smoking status, hypertension, Charlson Comorbidity Index, and type of intervention. RESULTS: There was an unequal sex distribution (77.6% male). The mean age was 72.1 years. One hundred and eighty-four patients (22.3%) were considered frail. The mean Comprehensive Complication Index was 8.5. Frail patients had a significantly higher Comprehensive Complication Index (3.7 point increase, p = .005). Patients with impaired cognition and reduced psychosocial condition, two domains of the GFI, had a significantly higher Comprehensive Complication Index. Also, the 30 day mortality rate was higher in frail patients (2.7 point increase; p = .05), and they were discharged to a care facility more often (7.7 point increase; p < .001). There was no significant difference in readmission rates between frail and non-frail patients. CONCLUSIONS: Frailty is associated with a higher risk of post-operative complications and discharge to a nursing home after vascular surgery. Some frailty domains (mobility, nutrition, cognition and psychosocial condition) appear to have a more pronounced impact

Role of pre-operative frailty status in relation to outcome after carotid endarterectomy:a systematic review

Carotid endarterectomy (CEA) is a surgical treatment option to prevent ischemic cerebrovascular accidents. Patients that present with pre-operative frailty might have an elevated risk for unfavorable outcomes after the CEA. A systematic search, using Medline, Embase, Web of Science and Cochrane Database, was performed for relevant literature on frailty in patients undergoing CEA. The study protocol was registered with PROSPERO (CRD42020190345). Eight articles were included. The pooled prevalence for pre-operative frailty was 23.9% (95% CI: 12.98-34.82). A difference in the incidence of complications between frail and non-frail patients (6.4% vs. 5.2%, respectively) and a difference in hospital length of stay [2 (IQR: 2-3) days vs. 1 (IQR: 1-2) day, respectively] were described. The 30-day mortality after CEA was 0.6% for non-frail patients, 2.6% for frail patients, and 4.9% for very frail patients (P 0.001). For 3-year mortality, a 1.5-fold increased risk was found for frail patients (OR 1.7, 95% CI: 1.4-2.0) and a &gt;2.5-fold increased risk for very frail patients (OR 2.6, 95% CI: 2.2-3.1). In conclusion, this review shows the impact of frailty on outcome after CEA. Pre-operative frailty assessment with a validated, multi-domain tool should be implemented in the clinical setting as it will provide information on post-operative surgical outcomes and mortality risk but also frailty trajectory and cognitive decline.</p

Surveys in Surgical Education:A Systematic Review and Reporting Guideline

Objectives: Survey studies are a commonly used method for data collection in surgical education research. Nevertheless, studies investigating survey design and response rates in surgical education research are lacking. The aim of this study was to gain an insight into survey response rates among surgical residents and medical students, and provide an initial reporting guideline for future survey studies in this field.Design: PubMed (MEDLINE) was systematically searched for survey studies in surgical education from January 2007 until February 2020, according to the PRISMA statements checklist. Study selection was conducted by 2 authors, independently. Surveys directed at surgical residents and/or medical students were included if data on response rates was available. Studies reporting solely from nonsurgical fields of medicine, paramedicine, or nursing were excluded. Subgroup analyses were performed, comparing response rates for varying modes of survey, per country, and for the 10 journals with the most identified surveys.Results: From the 5,693 records screened for a larger surgical survey database, a total of 312 surveys were included; 173 studies focused on surgical residents and 139 on medical students. The mean (SD) response rate was 55.7% (24.7%) for surgical residents and 69.0% (20.8%) for medical students. The number of published surveys increased yearly, mostly driven by an increase in surgical resident surveys. Although most surveys were Web-based (n = 166, 53.2%), this survey mode resulted in the lowest response rates (mean 52.6%). The highest response rates, with a mean of 79.8% (13.1%), were seen in in-person surveys (n = 89, 28.5%). Wide variations in response rates were seen between different countries and journals.Conclusions: Web-based surveys are gaining popularity for medical research in general and for surgical education specifically; however, this mode results in lower response rates than those of in-person surveys. The response rate of in-person surveys is especially high when focusing on medical students. To improve reporting of survey studies, we present the first step towards a reporting guideline.</p

Risk Factors for Delirium after Vascular Surgery:A Systematic Review and Meta-Analysis

Background: Vascular surgery is considered a risk factor for the development of postoperative delirium (POD). In this systematic review we provide a report on the incidence and risk-factors of POD after vascular surgery. Methods: A systematic literature search was conducted using Pubmed with the MeSH terms and key words "delirium" or "confusion", "vascular surgery procedures" and "risk factors or "risk assessment". Studies were selected for review after meeting the following inclusion cr iter ia: vascular surgery, POD diagnosed using validated screening tools, and DSM-derived criteria to assess delirium. A meta-analysis was performed for each endpoint if at least two studies could be combined. Results: Sixteen articles met the abovementioned cr iter ia. The incidence of delir ium ranged from 5% to 39%. Various preoperative risk factors were identified that is, age (Random MD 3.96, CI 2.57-5.35), hypertension (Fixed OR 1.30, CI 1.05-1.59), diabetes mellitus (Random OR 2.15, CI 1.30-3.56), hearing impairment (Fixed OR 1.89, CI 1.28-2.81), history of cerebrovascular incident or transient ischemic attack (Fixed OR 2.20, CI 1.68-2.88), renal failure (Fixed OR 1.61, CI 1.19-2.17), and pre-operative low haemoglobin level (fixed MD-0.76, CI-1.04 to-0.47). Intra-operative risk factors were duration of surgery (Random MD 15.68; CI 2.79-28.57), open aneurysm repair (Fixed OR 4.99, CI 3.10-8.03), aortic cross clamping time (fixed MD 7.99, CI 2.56-13.42), amputation surgery (random OR 3.77, CI 2.13-6.67), emergency surgery (Fixed OR 4.84, CI 2.81-8.32) and total blood loss (Random MD 496.5, CI 84.51-908.44) and need for blood transfusion (Random OR 3.72, CI 1.57-8.80). Regional anesthesia on the other hand, had a protective effect. Delirium was associated with longer ICU and hospital length of stay, and more frequent discharge to a care facility. Conclusions: POD after vascular surgery is a frequent complication and effect-size pooling supports the concept that delirium is a heterogeneous disorder. The risk factors identified can be used to either design a validated risk factor model or individual preventive strategies for high-risk patients

Predisposing and triggering factors of large-scale landslides in Debre Sina area, central Ethiopian highlands

A large number of landslide events have repeatedly struck the border zone of the northwestern plateaus of Ethiopia. Debre Sina area is one of the most tectonically active areas located along the western margin of the Afar depression, which is frequently affected by landslides. Despite that, urban and rural development is currently active in almost the entire area. It is crucial, therefore, to understand the main causes and failure mechanisms of landslides in the Debre Sina area and its surroundings. The present study investigated landslides using field mapping of geological and geomorphological features, remote sensing, geo-morphometric analysis, structural analysis, rainfall data, landslide inventory, and earthquake data. The results of the study indicate that large-scale and deep-seated landslide problems appear to be caused by complex geological settings and rugged topography. In particular, the location and morphology of the Yizaba Wein and Shotel Amba landslides are strongly controlled by geological structures. Their flanks are bounded by high angle faults, and their main basal failure surfaces have developed within a W–E striking eastward-dipping normal fault zone. The complex litho-structural and morphologic settings play a vital role in controlling the geometry of the slip surfaces and the stability of the landslides

Transition in Frailty State Among Elderly Patients After Vascular Surgery

BACKGROUND: Frailty in the vascular surgical ward is common and predicts poor surgical outcomes. The aim of this study was to analyze transitions in frailty state in elderly patients after vascular surgery and to evaluate influence of patient characteristics on this transition. METHODS: Between 2014 and 2018, 310 patients, ≥65 years and scheduled for elective vascular surgery, were included in this cohort study. Transition in frailty state between preoperative and follow-up measurement was determined using the Groningen Frailty Indicator (GFI), a validated tool to measure frailty in vascular surgery patients. Frailty is defined as a GFI score ≥4. Patient characteristics leading to a transition in frailty state were analyzed using multivariable Cox regression analysis. RESULTS: Mean age was 72.7 ± 5.2 years, and 74.5% were male. Mean follow-up time was 22.7 ± 9.5 months. At baseline measurement, 79 patients (25.5%) were considered frail. In total, 64 non-frail patients (20.6%) shifted to frail and 29 frail patients (9.4%) to non-frail. Frail patients with a high Charlson Comorbidity Index (HR = 0.329 (CI: 0.133-0.812), p = 0.016) and that underwent a major vascular intervention (HR = 0.365 (CI: 0.154-0.865), p = 0.022) had a significantly higher risk to remain frail after the intervention. CONCLUSIONS: The results of this study, showing that after vascular surgery almost 21% of the non-frail patients become frail, may lead to a more effective shared decision-making process when considering treatment options, by providing more insight in the postoperative frailty course of patients

Frailty leads to poor long-term survival in patients undergoing elective vascular surgery

Objective: Frailty has persistently been associated with unfavorable short-term outcomes after vascular surgery, including an increased complication risk, greater readmission rate, and greater short-term mortality. However, a knowledge gap remains concerning the association between preoperative frailty and long-term mortality. In the present study, we aimed to determine this association in elective vascular surgery patients. Methods: The present study was a part of a large prospective cohort study initiated in 2010 in our tertiary referral teaching hospital to study frailty in elderly elective vascular surgery patients (Vascular Ageing Study). A total of 639 patients with a minimal follow-up of 5 years, who had been treated from 2010 to 2014, were included in the present study. The Groningen Frailty Indicator, a 15-item self-administered questionnaire, was used to determine the presence and degree of frailty. Results: Of the 639 patients, 183 (28.6%) were considered frail preoperatively. For the frail patients, the actuarial survival after 1, 3, and 5 years was 81.4%, 66.7%, and 55.7%, respectively. For the nonfrail patients, the corresponding survival was 93.6%, 83.3%, and 75.2% (log-rank test, P Conclusions: The results of our study have shown that preoperative frailty is associated with significantly increased long-term mortality after elective vascular surgery. Knowledge of a patient's preoperative frailty state could, therefore, be helpful in shared decision-making, because it provides more information about the procedural benefits and risks

A review of clinical decision-making: Models and current research

Aims and objectives: The aim of this paper was to review the current literature with respect to clinical decision-making models and the educational application of models to clinical practice. This was achieved by exploring the function and related research of the three available models of clinical decision making: information processing model, the intuitive-humanist model and the clinical decision making model. Background: Clinical decision-making is a unique process that involves the interplay between knowledge of pre-existing pathological conditions, explicit patient information, nursing care and experiential learning. Historically, two models of clinical decision making are recognised from the literature; the information processing model and the intuitive-humanist model. The usefulness and application of both models has been examined in relation the provision of nursing care and care related outcomes. More recently a third model of clinical decision making has been proposed. This new multidimensional model contains elements of the information processing model but also examines patient specific elements that are necessary for cue and pattern recognition. Design: Literature review Methods: Evaluation of the literature generated from MEDLINE, CINAHL, OVID, PUBMED and EBESCO systems and the Internet from 1980 – November 2005