Long-Term Effects of Climate and Litter Chemistry on Rates and Stable Fractions of Decomposing Scots Pine and Norway Spruce Needle Litter—A Synthesis

We have reviewed information on early-, late- and limit-value decomposition stages for litter of Norway spruce (Picea abies) and Scots pine (Pinus silvestris). This synthesis covers c 16 studies/papers made along a climatic gradient; range in mean annual temperature (MAT) from −1 to +7 °C and mean annual precipitation (MAP) from 425 to 1070 mm. Scots pine has an early stage dominated by carbohydrate decomposition and a late stage dominated by decomposition of lignin; Norway spruce has just one stage dominated by lignin decomposition. We used data for annual mass loss to identify rate-regulating factors in both stages; climate data, namely, MAT and MAP, as well as substrate properties, namely, nitrogen (N), acid unhydrolyzable residue (AUR), manganese (Mn). Early-stage decomposition for Scots pine litter was dominated positively by MAT; the late stage was dominated negatively by MAT, N, and AUR, changing with decomposition stage; there was no effect of Mn. Norway spruce litter had no early stage; decomposition in the lignin-dominated stage was mainly negative to MAP, a negative relationship to AUR and non-significant relationships to N and MAT. Mn had a positive relationship. Limit values for decomposition, namely, the accumulated mass loss at which decomposition is calculated to be zero, were related positively to Mn and AUR for Scots pine litter and negatively to AUR for Norway spruce litter. With different sets of rate-regulating factors as well as different compounds/elements related to the limit values, the decomposition patterns or pathways are different.

Caregiver Burden and Quality of Life in Late Stage Parkinson’s Disease

Parkinson’s disease (PD) is a chronic, progressive, neurodegenerative disease involving both motor and non-motor symptoms (NMS). In the late stage of the disease, Hoehn and Yahr (H&Y) stage IV-V, the symptomatology is often severe and patients become increasingly dependent on help in their daily life, resulting in an increased burden for the informal caregivers. To assess the implications of the caregiver burden, caregiver quality of life (QoL) was assessed in 74 informal caregivers to patients in late stage PD, by the Alzheimer’s Patient Partners Life Impact Questionnaire (APPLIQue), which has been found useful also in PD. The majority of caregivers were the spouse/partner. Individual items provided information on which aspects of caregiver burden were the most common, i.e., items: “feel guilty if not there (71% affirmed)”, “the situation wears me down” (65% affirmed) and “always on my mind” (61% affirmed). In simple linear regression analyses, male patient gender (p = 0.007), better cognition (p = 0.004), lower NMS burden (p = 0.012) and not being the partner (p = 0.022) were associated with better caregiver QoL. Multivariable linear regression analyses identified better cognition (p = 0.004) and male patient gender (p = 0.035) as independently associated with better informal caregiver QoL. Identifying and treating NMS as well as recognizing and alleviating caregiver burden seem essential to enhance QoL for both patients and caregivers in late stage PD.

Metagenomic and Metatranscriptomic Responses of Chemical Dispersant Application during a Marine Dilbit Spill

The global increase in marine transportation of dilbit (diluted bitumen) can increase the risk of spills, and the application of chemical dispersants remains a common response practice in spill events. To reliably evaluate dispersant effects on dilbit biodegradation over time, we set large-scale (1500 mL) microcosms without nutrients addition using low dilbit concentration (30 ppm). Shotgun metagenomics and metatranscriptomics were deployed to investigate microbial community responses to naturally and chemically dispersed dilbit. We found that the large-scale microcosms could produce more reproducible community trajectories than small-scale (250 mL) ones based on the 16S rRNA gene amplicon sequencing. In the early-stage large-scale microcosms, multiple genera were involved into the biodegradation of dilbit, while dispersant addition enriched primarily Alteromonas and competed for the utilization of dilbit, causing depressed degradation of aromatics. The metatranscriptomic based Metagenome Assembled Genomes (MAG) further elucidated early-stage microbial antioxidation mechanism, which showed dispersant addition triggered the increased expression of the antioxidation process genes of Alteromonas species. Differently, in the late stage, the microbial communities showed high diversity and richness and similar compositions and metabolic functions regardless of dispersant addition, indicating the biotransformation of remaining compounds can occur within the post-oil communities. These findings can guide future microcosm studies and the application of chemical dispersants for responding to a marine dilbit spill. Importance In this study, we employed microcosms to study the effects of marine dilbit spill and dispersant application on microbial community dynamics over time. We evaluated the impacts of microcosm scale and found that increasing the scale is beneficial for reducing community stochasticity, especially in the late stage of biodegradation. We observed that dispersant application suppressed aromatics biodegradation in the early stage (6 days) whereas exerting insignificant effects in the late stage (50 days), from both substances removal and metagenomic/metatranscriptomic perspectives. We further found that Alteromonas species are vital for the early-stage chemically dispersed oil biodegradation, and clarified their degradation and antioxidation mechanisms. The findings would help to better understand microcosm studies and microbial roles for biodegrading dilbit and chemically dispersed dilbit, and suggest that dispersant evaluation in large-scale systems and even through field trails would be more realistic after marine oil spill response.

Adaptation to an amoeba host leads to Pseudomonas aeruginosa isolates with attenuated virulence

The opportunistic pathogen Pseudomonas aeruginosa , is ubiquitous in the environment, and in humans is capable of causing acute or chronic infections. In the natural environment, predation by bacterivorous protozoa represents a primary threat to bacteria. Here, we determined the impact of long-term exposure of P. aeruginosa to predation pressure. P. aeruginosa persisted when co-incubated with the bacterivorous Acanthamoeba castellanii for extended periods and produced genetic and phenotypic variants. Sequencing of late-stage amoeba-adapted P. aeruginosa isolates demonstrated single nucleotide polymorphisms within genes that encode known virulence factors and this correlated with a reduction in expression of virulence traits. Virulence towards the nematode, Caenorhabditis elegans , was attenuated in late-stage amoeba-adapted P. aeruginosa compared to early-stage amoeba-adapted and non-adapted counterparts. Further, late-stage amoeba-adapted P. aeruginosa showed increased competitive fitness and enhanced survival in amoeba as well as in macrophage and neutrophils. Interestingly, our findings indicate that the selection imposed by amoeba resulted in P. aeruginosa isolates with reduced virulence and enhanced fitness, similar to those recovered from chronic cystic fibrosis infections. Thus, predation by protozoa and long-term colonization of the human host may represent similar environments that select for similar losses of gene function. Importance Pseudomonas aeruginosa is an opportunistic pathogen that causes both acute infections in plants and animals, including humans, and chronic infections in immunocompromised and cystic fibrosis patients. This bacterium is commonly found in soils and water where bacteria are constantly under threat of being consumed by bacterial predators, e.g. protozoa. To escape being killed, bacteria have evolved a suite of mechanisms that protect them from being consumed or digested. Here, we examine the effect of long-term predation on the genotypes and phenotypes expressed by P. aeruginosa . We show that long term co-incubation with protozoa resulted in mutations that resulted in P. aeruginosa becoming less pathogenic. This is particularly interesting as we see similar mutations arise in bacteria associated with chronic infections. Importantly, the genetic and phenotypic traits possessed by late-stage amoeba-adapted P. aeruginosa are similar to what is observed for isolates obtained from chronic cystic fibrosis infections. This notable overlap in adaptation to different host types suggests similar selection pressures amongst host cell types as well as similar adaptation strategies.

A review of late-stage tungsten fuzz growth

Tungsten will be used as the plasma-facing divertor material in the International Thermonuclear Experimental Reactor (ITER) fusion reactor. Under high temperatures and high ion fluxes, a ‘fuzz’ nanostructure forms on the tungsten surface with dramatically different properties and could contaminate the plasma. Although simulations and experimental observations have provided understanding of the initial fuzz formation process, there is debate over whether tungsten or helium migration is rate-limiting during late-stage growth, and the mechanisms by which tungsten and helium migrations occur. Here, the proposed mechanisms are considered in turn. It is concluded that tungsten migration occurs by adatom diffusion along the fuzz surface. Continual helium migration through the porous fuzz to the tungsten bulk is also required for fuzz growth, for continued bubble growth and rupture. Helium likely migrates due to ballistic penetration, although diffusion may contribute. It is difficult to determine the limiting process, which may switch from helium penetration to tungsten adatom diffusion above a threshold flux. Areas for further research to clarify the mechanisms are then considered. A greater understanding of the fuzz formation mechanism is key to the successful design of plasma-facing tungsten components, and may have applications in forming porous tungsten catalysts.

Drivers of Disparities in Stage at Diagnosis Among Women With Breast Cancer: South African Breast Cancers and HIV Outcomes Cohort

Objective In low- and middle-income countries (LMICs), advanced stage diagnosis of breast cancer (BC) is common, and this contributes to poor survival. By understanding the determinants of the stage at diagnosis will aid in designing interventions to downstage disease and improve survival from BC in LMICs. MethodsWithin the South African Breast Cancers and HIV Outcomes (SABCHO) cohort, we examined factors affecting the stage at diagnosis of histologically confirmed invasive breast cancer at five tertiary hospitals in South Africa. The stage was assessed clinically. To examine the associations of the health system, socio-economic/household and individual factors, hierarchical multivariate logistic regression with odds of late-stage at diagnosis (stage III-IV), was used. Results The majority (59%) of the included 3497 women were diagnosed with late-stage BC disease (59%). The effect of health system-level factors on late-stage BC diagnosis was consistent and significant even when adjusted for both socio-economic- and individual-level factors. Women diagnosed in a tertiary hospital that predominantly serves a rural population were almost 3 times (OR=2.89 (95% CI: 1.40-5.97) likely to be associated with late-stage BC diagnosis when compared to those diagnosed at a hospital that predominantly serves an urban population. Taking more than 3 months from identifying the BC problem to first health system entry (OR=1.66 (95% CI: 1.38–2.00)), and receptor subtypes [luminal B (OR=1.49 (95% CI: 1.19–1.87)), HER2 enriched (OR=1.64 (95% CI: 1.16–2.32))] were associated with a late-stage diagnosis. Whilst having a higher socio-economic level (a wealth index of 5) reduced the probability of late-stage BC, OR=0.64 (95% CI: 0.47 – 0.85). ConclusionAdvanced stage diagnosis of BC among women in SA who access health services through the public health system was associated with both modifiable health system-level factors and non-modifiable individual-level factors. These may be considered as elements in interventions to reduce the time to diagnosis of breast cancer in women.

FOREIGN BODY INCIDENCE IN PREGNANT COWS AND BUFFALOS

Clinical study for (105) pregnant and (32) buffalo suffering from reticulopertonitis which are operated for foreign body removal by rumenotomy in different pregnancy stages. Result shown that the late stage pregnancy is the highest inicdence and all operated animals had no any complications and some of them delivered normally after 10 - 16 hr. and other within few days, this indicate that rumenotomy could be done at any stage of pregnancy even within few hours before parturition.