986 research outputs found
Life Cycle Assessment across the Food Supply Chain
The environmental impact is one of the major pillars of concerns when addressing the sustainability of food production and sustainable food consumption strategies.
To assess to what extent food production affects the environment, one needs to choose a proper environmental assessment tool. Different types of assessment tools have been developed to establish environmental indicators, which can be used to determine the environmental impact of livestock production systems or agricultural products. The environmen¬tal assessment tools can be divided into the area based or product based (Halberg et al., 2005). Area-based indicators are, for example, nitrate leached per hectare from a pig farm, and product-based indicators are, for example, global warming potential per kg pork (Dalgaard, 2007).
The area-based indicators are useful for evaluating farm emissions of nutrients such as nitrate that has an effect on the local environment. On the other hand, when considering the greenhouse gas emissions from the agricultural production, the product-based indicators are useful for evaluating the impact of food productions on the global environment (e. g., climate change) and have the advantage that in addition to emis-sions from the farms, emissions related to the production of input s (e.g., soybean and artificial fertilizer) and outputs (e.g., slurry exported to other farms) are also included. In that way it is easier to avoid pollution swapping, which means that the solving of one pollution problem creates a new (Dalgaard, 2007)
Identification of a novel type of spacer element required for imprinting in fission yeast
Asymmetrical segregation of differentiated sister chromatids is thought to be important for cellular differentiation in higher
eukaryotes. Similarly, in fission yeast, cellular differentiation involves the asymmetrical segregation of a chromosomal
imprint. This imprint has been shown to consist of two ribonucleotides that are incorporated into the DNA during laggingstrand
synthesis in response to a replication pause, but the underlying mechanism remains unknown. Here we present key
novel discoveries important for unravelling this process. Our data show that cis-acting sequences within the mat1 cassette
mediate pausing of replication forks at the proximity of the imprinting site, and the results suggest that this pause dictates
specific priming at the position of imprinting in a sequence-independent manner. Also, we identify a novel type of cis-acting
spacer region important for the imprinting process that affects where subsequent primers are put down after the
replication fork is released from the pause. Thus, our data suggest that the imprint is formed by ligation of a not-fullyprocessed
Okazaki fragment to the subsequent fragment. The presented work addresses how differentiated sister
chromatids are established during DNA replication through the involvement of replication barriers
Synergistic disruption of external male sex organ development by a mixture of four antiandrogens
Reproduced with permission from Environmental Health Perspectives.Background: By disrupting the action of androgens during gestation, certain chemicals present in food, consumer products, and the environment can induce irreversible demasculinization and malformations of sex organs among male offspring. However, the consequences of simultaneous exposure to such chemicals are not well described, especially when they exert their actions by differing molecular mechanisms.
Objectives: To fill this gap, we investigated the effects of mixtures of a widely used plasticizer, di(2-ethylhexyl) phthalate (DEHP); two fungicides present in food, vinclozolin and prochloraz; and a pharmaceutical, finasteride, on landmarks of male sexual development in the rat, including changes in anogenital distance (AGD), retained nipples, sex organ weights, and malformations of genitalia. These chemicals were chosen because they disrupt androgen action with differing mechanisms of action.
Results: Strikingly, the effect of combined exposure to the selected chemicals on malformations of external sex organs was synergistic, and the observed responses were greater than would be predicted from the toxicities of the individual chemicals. In relation to other hallmarks of disrupted male sexual development, including changes in AGD, retained nipples, and sex organ weights, the combined effects were dose additive. When the four chemicals were combined at doses equal to no observed adverse effect levels estimated for nipple retention, significant reductions in AGD were observed in male offspring.
Conclusions: Because unhindered androgen action is essential for human male development in fetal life, these findings are highly relevant to human risk assessment. Evaluations that ignore the possibility of combination effects may lead to considerable underestimations of risks associated with exposures to chemicals that disrupt male sexual differentiation.European Union and the Danish Environmental Protection Agency
Comparison of global gene expression profiles of microdissected human foetal Leydig cells with their normal and hyperplastic adult equivalents
Heterogeneous distribution of plankton within the mixed layer and its implications for bloom formation in tropical seas
Intensive sampling at the coastal waters of the central Red Sea during a period of thermal stratification, prior to the main seasonal bloom during winter, showed that vertical patches of prokaryotes and microplankton developed and persisted for several days within the apparently density uniform upper layer. These vertical structures were most likely the result of in situ growth and mortality (e.g., grazing) rather than physical or behavioural aggregation. Simulating a mixing event by adding nutrient-rich deep water abruptly triggered dense phytoplankton blooms in the nutrient-poor environment of the upper layer. These findings suggest that vertical structures within the mixed layer provide critical seeding stocks that can rapidly exploit nutrient influx during mixing, leading to winter bloom formation
Review of biorthogonal coupled cluster representations for electronic excitation
Single reference coupled-cluster (CC) methods for electronic excitation are
based on a biorthogonal representation (bCC) of the (shifted) Hamiltonian in
terms of excited CC states, also referred to as correlated excited (CE) states,
and an associated set of states biorthogonal to the CE states, the latter being
essentially configuration interaction (CI) configurations. The bCC
representation generates a non-hermitian secular matrix, the eigenvalues
representing excitation energies, while the corresponding spectral intensities
are to be derived from both the left and right eigenvectors. Using the
perspective of the bCC representation, a systematic and comprehensive analysis
of the excited-state CC methods is given, extending and generalizing previous
such studies. Here, the essential topics are the truncation error
characteristics and the separability properties, the latter being crucial for
designing size-consistent approximation schemes. Based on the general order
relations for the bCC secular matrix and the (left and right) eigenvector
matrices, formulas for the perturbation-theoretical (PT) order of the
truncation errors (TEO) are derived for energies, transition moments, and
property matrix elements of arbitrary excitation classes and truncation levels.
In the analysis of the separability properties of the transition moments, the
decisive role of the so-called dual ground state is revealed. Due to the use of
CE states the bCC approach can be compared to so-called intermediate state
representation (ISR) methods based exclusively on suitably orthonormalized CE
states. As the present analysis shows, the bCC approach has decisive advantages
over the conventional CI treatment, but also distinctly weaker TEO and
separability properties in comparison with a full (and hermitian) ISR method
Klinefelter syndrome comorbidities linked to increased X chromosome gene dosage and altered protein interactome activity
Klinefelter syndrome (KS) (47,XXY) is the most common male sex chromosome aneuploidy. Diagnosis and clinical supervision remain a challenge due to varying phenotypic presentation and insufficient characterization of the syndrome. Here we combine health data-driven epidemiology and molecular level systems biology to improve the understanding of KS and the molecular interplay influencing its comorbidities. In total, 78 overrepresented KS comorbidities were identified using in- and out-patient registry data from the entire Danish population covering 6.8 million individuals. The comorbidities extracted included both clinically well-known (e.g. infertility and osteoporosis) and still less established KS comorbidities (e.g. pituitary gland hypofunction and dental caries). Several systems biology approaches were applied to identify key molecular players underlying KS comorbidities: Identification of co-expressed modules as well as central hubs and gene dosage perturbed protein complexes in a KS comorbidity network build from known disease proteins and their protein–protein interactions. The systems biology approaches together pointed to novel aspects of KS disease phenotypes including perturbed Jak-STAT pathway, dysregulated genes important for disturbed immune system (IL4), energy balance (POMC and LEP) and erythropoietin signalling in KS. We present an extended epidemiological study that links KS comorbidities to the molecular level and identify potential causal players in the disease biology underlying the identified comorbidities
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The transmission of trauma in refugee families: associations between intra-family trauma communication style, children’s attachment security and psychosocial adjustment
This study explores the transmission of trauma in 30 Middle Eastern refugee families in Denmark, where one or both parents were referred for treatment of PTSD symptoms and had non-traumatized children aged 4–9 years. The aim of the study was to explore potential risk and protective factors by examining the association between intra-family communication style regarding the parents’ traumatic experiences from the past, children’s psychosocial adjustment and attachment security. A negative impact of parental trauma on children might be indicated, as children’s Total Difficulties Scores on the Strengths and Difficulties Questionnaire (SDQ) were significantly higher than the Danish norms. A negative association between children’s attachment security as measured by the Attachment and Traumatization Story Task and higher scores on the SDQ Total Difficulties Scale approached significance, suggesting that the transmission of trauma may be associated with disruptions in children’s attachment representations. Furthermore a significant association between parental trauma communication and children’s attachment style was found
Monopolin subunit Csm1 associates with MIND complex to establish monopolar attachment of sister kinetochores at meiosis I
Sexually reproducing organisms halve their cellular ploidy during gametogenesis by undergoing a specialized form of cell division known as meiosis. During meiosis, a single round of DNA replication is followed by two rounds of nuclear divisions (referred to as meiosis I and II). While sister kinetochores bind to microtubules emanating from opposite spindle poles during mitosis, they bind to microtubules originating from the same spindle pole during meiosis I. This phenomenon is referred to as mono-orientation and is essential for setting up the reductional mode of chromosome segregation during meiosis I. In budding yeast, mono-orientation depends on a four component protein complex referred to as monopolin which consists of two nucleolar proteins Csm1 and Lrs4, meiosis-specific protein Mam1 of unknown function and casein kinase Hrr25. Monopolin complex binds to kinetochores during meiosis I and prevents bipolar attachments. Although monopolin associates with kinetochores during meiosis I, its binding site(s) on the kinetochore is not known and its mechanism of action has not been established. By carrying out an imaging-based screen we have found that the MIND complex, a component of the central kinetochore, is required for monopolin association with kinetochores during meiosis. Furthermore, we demonstrate that interaction of monopolin subunit Csm1 with the N-terminal domain of MIND complex subunit Dsn1, is essential for both the association of monopolin with kinetochores and for monopolar attachment of sister kinetochores during meiosis I. As such this provides the first functional evidence for a monopolin-binding site at the kinetochore
Gradient microfluidics enables rapid bacterial growth inhibition testing
Bacterial growth inhibition tests have become a standard measure of the adverse effects of inhibitors for a wide range of applications, such as toxicity testing in the medical and environmental sciences. However, conventional well-plate formats for these tests are laborious and provide limited information (often being restricted to an end-point assay). In this study, we have developed a microfluidic system that enables fast quantification of the effect of an inhibitor on bacteria growth and survival, within a single experiment. This format offers a unique combination of advantages, including long-term continuous flow culture, generation of concentration gradients, and single cell morphology tracking. Using Escherichia coli and the inhibitor amoxicillin as one model system, we show excellent agreement between an on-chip single cell-based assay and conventional methods to obtain quantitative measures of antibiotic inhibition (for example, minimum inhibition concentration). Furthermore, we show that our methods can provide additional information, over and above that of the standard well-plate assay, including kinetic information on growth inhibition and measurements of bacterial morphological dynamics over a wide range of inhibitor concentrations. Finally, using a second model system, we show that this chip-based systems does not require the bacteria to be labeled and is well suited for the study of naturally occurring species. We illustrate this using Nitrosomonas europaea, an environmentally important bacteria, and show that the chip system can lead to a significant reduction in the period required for growth and inhibition measurements (<4 days, compared to weeks in a culture flask)
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