Baseline time accounting: Considering global land use dynamics when estimating the climate impact of indirect land use change caused by biofuels

Purpose

Current estimations of the climate impact from indirect land use change (ILUC) caused by biofuels are heavily influenced by assumptions regarding the biofuel production period. The purpose of this paper is to propose a new method (baseline time accounting) that takes global land use dynamics into account that is consistent with the global warming potential, that is applicable to any phenomenon causing land use change, and that is independent of production period assumptions.

Methods

We consider ILUC in two forms. The first is called “accelerated expansion” and concerns ILUC in regions with an expanding agricultural area. The second is called “delayed reversion” and concerns ILUC in regions with a decreasing agricultural area. We use recent trends in international land use and projections of future land use change to assess how ILUC from biofuels will alter the development in global agricultural land use dynamics compared to the existing trend (i.e., the baseline development). We then use the definition of the global warming potential to determine the CO₂ equivalence of the change in land use dynamics.

Results and discussion

We apply baseline time accounting to two existing ILUC studies in the literature. With current trends in global agricultural land use, the method significantly reduces the estimated climate impact in the previous ILUC studies (by more than half). Sensitivity analyses show that results are somewhat sensitive to assumptions regarding carbon sequestration and assumptions regarding postreversion ecosystems.

Conclusions

The global dynamic development in land use has important implications for the time accounting step when estimating the climate impact of ILUC caused by biofuel production or other issues affecting land use. Ignoring this may lead to erroneous conclusions about the actual climate impact of ILUC. Several land use projections indicate that the global agricultural area will keep expanding up to and beyond 2050. We therefore recommend to apply the baseline time accounting concept as an integrated part of future ILUC studies and to update the results on a regular basis.     

Prevalence of Human Papillomavirus in 5,072 Consecutive Cervical SurePath Samples Evaluated with the Roche Cobas HPV Real-Time PCR Assay

New commercially available Human Papillomavirus (HPV) assays need to be evaluated in a variety of cervical screening settings. Cobas HPV Test (cobas) is a real-time PCR-based assay allowing for separate detection of HPV genotypes 16 and 18 and a bulk of 12 other high-risk genotypes. The aim of the present study, Horizon, was to assess the prevalence of high-risk HPV infections in an area with a high background risk of cervical cancer, where women aged 23–65 years are targeted for cervical screening. We collected 6,258 consecutive cervical samples from the largest cervical screening laboratory in Denmark serving the whole of Copenhagen. All samples were stored in SurePath media. In total, 5,072 samples were tested with cobas, Hybrid Capture 2 High Risk HPV DNA test (HC2) and liquid-based cytology. Of these, 27% tested positive on cobas. This proportion decreased by age, being 43% in women aged 23–29 years and 10% in women aged 60–65 years. HC2 assay was positive in 20% of samples, and cytology was abnormal (≥ atypical squamous cells of undetermined significance) for 7% samples. When only samples without recent abnormalities were taken into account, 24% tested positive on cobas, 19% on HC2, and 5% had abnormal cytology. The proportion of positive cobas samples was higher than in the ATHENA trial. The age-standardized cobas positivity vs. cytology abnormality was 3.9 in our study and 1.7 in ATHENA. If in Copenhagen the presently used cytology would be replaced by cobas in women above age 30 years, an extra 11% of women would based on historical data be expected to have a positive cobas test without an underlying cervical intraepithelial lesion grade 3 or worse. Countries with a high prevalence of HPV infections should therefore proceed to primary HPV-based cervical screening with caution.     

Size,Accumulation and Performance for Research Grants: Examining the Role of Size for Centres of Excellence

The present paper examines the relation between size, accumulation and performance for research grants, where we examine the relation between grant size for Centres of Excellence (CoE) funded by the Danish National Research Foundation (DNRF) and various ex post research performance measures, including impact and shares of highly cited articles. We examine both the relation between size and performance and also how performance for CoEs evolves over the course of grant periods. In terms of dynamics, it appears that performance over the grant period (i.e. 10 years) is falling for the largest CoEs, while it is increasing for those among the smallest half. Overall, multivariate econometric analysis finds evidence that performance is increasing in grant size and over time. In both cases, the relation appears to be non-linear, suggesting that there is a point at which performance peaks. The CoEs have also been very successful in securing additional funding, which can be viewed as a ‘cumulative effect’ of center grants. In terms of new personnel, the far majority of additional funding is spent on early career researchers, hence, this accumulation would appear to have a ‘generational’ dimension, allowing for scientific expertise to be passed on to an increasing number of younger researchers.     

Conformation-specific anti-Mad2 monoclonal antibodies for the dissection of checkpoint signaling

The spindle assembly checkpoint (SAC) ensures accurate chromosome segregation during mitosis by delaying the activation of the anaphase-promoting complex/cyclosome (APC/C) in response to unattached kinetochores. The Mad2 protein is essential for a functional checkpoint because it binds directly to Cdc20, the mitotic co-activator of the APC/C, thereby inhibiting progression into anaphase. Mad2 exists in at least 2 different conformations, open-Mad2 (O-Mad2) and closed-Mad2 (C-Mad2), with the latter representing the active form that is able to bind Cdc20. Our ability to dissect Mad2 biology in vivo is limited by the absence of monoclonal antibodies (mAbs) useful for recognizing the different conformations of Mad2. Here, we describe and extensively characterize mAbs specific for either O-Mad2 or C-Mad2, as well as a pan-Mad2 antibody, and use these to investigate the different Mad2 complexes present in mitotic cells. Our antibodies validate current Mad2 models but also suggest that O-Mad2 can associate with checkpoint complexes, most likely through dimerization with C-Mad2. Furthermore, we investigate the makeup of checkpoint complexes bound to the APC/C, which indicate the presence of both Cdc20-BubR1-Bub3 and Mad2-Cdc20-BubR1-Bub3 complexes, with Cdc20 being ubiquitinated in both. Thus, our defined mAbs provide insight into checkpoint signaling and provide useful tools for future research on Mad2 function and regulation.     

Elevated p16ink4a Expression in Human Labial Salivary Glands as a Potential Correlate of Cognitive Aging in Late Midlife

Background

The cell-cycle inhibitor and tumor suppressor cyclin dependent kinase inhibitor, p16^ink4a, is one of the two gene products of the ink4a/ARF (cdkn2a) locus on chromosome 9q21. Up-regulation of p16^ink4a has been linked to cellular senescence, and findings from studies on different mammalian tissues suggest that p16^ink4a may be a biomarker of organismal versus chronological age.

Objective

The aim of this study was to examine the immunolocalization pattern of p16^ink4a in human labial salivary gland (LSG) tissue, and to analyze whether its expression level in LSGs is a peripheral correlate of cognitive decline in late midlife.

Methods

The present study was a part of a study of causes and predictors of cognitive decline in middle-aged men in a Danish birth cohort. It is based on data from 181 male participants from the Danish Metropolit birth cohort, born in 1953, who were examined for age-associated alterations in cognition, dental health, and morphological and autonomic innervation characteristics of the LSGs. The participants were allocated to two groups based on the relative change in cognitive performance from young adulthood to late midlife. LSG biopsies were analyzed by qRT-PCR for the expression level of p16^ink4a. Immunohistochemistry was performed on formalin-fixed, paraffin-embedded sections of LSGs.

Results

p16^ink4a immunoreactivity was observed in LSG ductal, myoepithelial, and stromal cells, but not in acinar cells. The mean relative expression of p16^ink4a in LSGs was higher in the group of participants with decline in cognitive performance. A logistic regression analysis revealed that the relative p16 expression was predictive of the participant’s group assignment. A negative correlation was found between relative p16^ink4a expression and the participant’s standardized regression residuals from early adulthood to late midlife cognitive performance scores.

Conclusions

p16^ink4a expression in human LSGs may constitute a potential peripheral correlate of cognitive decline. Human labial salivary glands seem suitable for studies on organismal as opposed to chronological age.     

Internal Jugular Vein Cross-Sectional Area Enlargement Is Associated with Aging in Healthy Individuals

Background

Internal jugular vein (IJV) narrowing has been implicated in central nervous system pathologies, however normal physiological age- and gender-related IJV variance in healthy individuals (HIs) has not been adequately assessed.

Objectives

We assessed the relationship between IJV cross-sectional area (CSA) and aging.

Materials and Methods

This study involved 193 HIs (63 males and 130 females) who received 2-dimensional magnetic resonance venography at 3T. The minimum CSA of the IJVs at cervical levels C2/C3, C4, C5/C6, and C7/T1 was obtained using a semi-automated contouring-thresholding technique. Subjects were grouped by decade. Pearson and partial correlation (controlled for cardiovascular risk factors, including hypertension, heart disease, smoking and body mass index) and analysis of variance analyses were used, with paired t-tests comparing side differences.

Results

Mean right IJV CSA ranges were: in males, 41.6 mm² (C2/C3) to 82.0 mm² (C7/T1); in females, 38.0 mm² (C2/C3) to 62.3 mm² (C7/T1), while the equivalent left side ranges were: in males, 28.0 mm² (C2/C3) to 52.2 mm² (C7/T1); in females, 27.2 mm² (C2/C3) to 47.8 mm² (C7/T1). The CSA of the right IJVs was significantly larger (p<0.001) than the left at all cervical levels. Controlling for cardiovascular risk factors, the correlation between age and IJV CSA was more robust in males than in the females for all cervical levels.

Conclusions

In HIs age, gender, hand side and cervical location all affect IJV CSA. These findings suggest that any definition of IJV stenosis needs to account for these factors.     

Population and Single-Cell Analysis of Human Cardiogenesis Reveals Unique LGR5 Ventricular Progenitors in Embryonic Outflow Tract

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Serum tau fragments as predictors of death or poor neurological outcome after out-of-hospital cardiac arrest

Background: Anoxic brain injury is the primary cause of death after resuscitation from out-of-hospital cardiac arrest (OHCA) and prognostication is challenging. The aim of this study was to evaluate the potential of two fragments of tau as serum biomarkers for neurological outcome.

Methods: Single-center sub-study of 171 patients included in the Target Temperature Management (TTM) Trial randomly assigned to TTM at 33?°C or TTM at 36?°C for 24?h after OHCA. Fragments (tau-A and tau-C) of the neuronal protein tau were measured in serum 24, 48 and 72?h after OHCA. The primary endpoint was neurological outcome.

Results: Median (quartile 1 – quartile 3) tau-A (ng/ml) values were 58 (43–71) versus 51 (43–67), 72 (57–84) versus 71 (59–82) and 76 (61–92) versus 75 (64–89) for good versus unfavourable outcome at 24, 48 and 72?h, respectively (p_group = 0.95). Median tau C (ng/ml) values were 38 (29–50) versus 36 (29–49), 49 (38–58) versus 48 (33–59) and 48 (39–59) versus 48 (36–62) (p_group = 0.95). Tau-A and tau-C did not predict neurological outcome (area under the receiver-operating curve at 48?h; tau-A: 0.51 and tau-C: 0.51).

Conclusions: Serum levels of tau fragments were unable to predict neurological outcome after OHCA.     

Muskoxen Modify Plant Abundance,Phenology, and Nitrogen Dynamics in a High Arctic Fen

Ecosystems - Herbivores are key drivers of vegetation dynamics in most ecosystems. However, the effect of high arctic herbivores on vegetation dynamics throughout a growing season is not well...