Forest restoration following a windthrow: how legacy retention versus plantation after salvaging alters the trajectory of initial recovery

Recently, the conversion of plantations into natural forests has attracted increasing attention, but little is known about how to convert a windthrown plantation into a natural forest. We examined the initial 3-year effects of salvage logging, site preparation, planting, and weeding in comparison with the effects of legacy retention after a typhoon blowdown on the changes in terrestrial environments and plant compositions and the similarity of the species composition to that of the intact natural forest. Our major findings are as follows: (1) A homogeneous, sunny, and flat environment continued for 3 years in the planted and weeded plot, whereas a heterogeneous environment was observed in the legacy retention plot; however, the light environment changed slightly in the planted plot. (2) The species composition in the planted plots changed greatly due to invasion by annual, biennial, and perennial herbs and early successional trees. Alien species also invaded the planted row. Conversely, the species composition changed little in the legacy retention, which was likely due to the presence of residual plants that prevented shade-intolerant species from being established. (3) The legacy retention, followed by the residual row, was the closest to the natural forest with respect to species composition, whereas the planted row was the most dissimilar from the natural forest. Legacy retention appears to be the most appropriate way to restore a natural forest immediately after a windthrow, yet supplemental planting may be necessary to restore the desired broadleaved species.     

Dentists’ Dietary Perception and Practice Patterns in a Dental Practice-Based Research Network

Background

Dental caries are largely preventable, and epidemiological evidence for a relationship between diet and oral health is abundant. To date, however, dentists’ perceptions about the role of diet and dentists’ practice patterns regarding diet counseling have not been clarified.

Objective

The purposes of this study were to: (1) examine discordance between dentists’ perception of the importance of diet in caries treatment planning and their actual provision of diet counseling to patients, and (2) identify dentists’ characteristics associated with their provision of diet counseling.

Design

The study used a cross-sectional study design consisting of a questionnaire survey in Japan.

Participants

The study queried dentists working in outpatient dental practices who were affiliated with the Dental Practice-Based Research Network Japan (JDPBRN), which aims to allow dentists to investigate research questions and share experiences and expertise (n = 282).

Measurement

Dentists were asked about their perceptions on the importance of diet and their practice patterns regarding diet counseling, as well as patient, practice, and dentist background data.

Results

The majority of participants (n = 116, 63%) recognized that diet is “more important” to oral health. However, among participants who think diet is “more important” (n = 116), only 48% (n = 56) provide diet counseling to more than 20% of their patients. Multiple logistic regression analysis suggested that several variables were associated with providing diet counseling; dentist gender, practice busyness, percentage of patients interested in caries prevention, caries risk assessment, and percentage of patients who receive blood pressure screening.

Conclusions

Some discordance exists between dentists’ perception of the importance of diet in caries treatment planning and their actual practice pattern regarding diet counseling to patients. Reducing this discordance may require additional dentist education, including nutritional and systemic disease concepts; patient education to increase perception of the importance of caries prevention; or removing barriers to practices’ implementation of counseling.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01680848","term_id":"NCT01680848"}}NCT01680848     

Relationship between gyrA mutations and quinolone resistance in Flavobacterium psychrophilum isolates

Flavobacterium psychrophilum is the causative agent of the fish diseases called bacterial cold-water disease and rainbow trout fry syndrome. It has been reported that some isolates of F. psychrophilum are resistant to quinolones; however, the mechanism of this quinolone resistance has been unexplained. In this study, we examined the quinolone susceptibility patterns of 27 F. psychrophilum strains isolated in Japan and the United States. Out of 27 isolates, 14 were resistant to both nalidixic acid (NA) and oxolinic acid (OXA), and the others were susceptible to NA and OXA. When amino acid sequences deduced from gyrA nucleotide sequences of all isolates tested were analyzed, two amino acid substitutions (a threonine residue replaced by an alanine or isoleucine residue in position 83 of GyrA [Escherichia coli numbering] and an aspartic acid residue replaced by a tyrosine residue in position 87) were observed in the 14 quinolone-resistant isolates. These results strongly suggest that, as in other gram-negative bacteria, DNA gyrase is an important target for quinolones in F. psychrophilum.     

Nerve growth factor-induced glutamate release is via p75 receptor,ceramide, and Ca(2+) from ryanodine receptor in developing cerebellar neurons

Very little is known about the contribution of a low affinity neurotrophin receptor, p75, to neurotransmitter release. Here we show that nerve growth factor (NGF) induced a rapid release of glutamate and an increase of Ca2+ in cerebellar neurons through a p75-dependent pathway. The NGF-induced release occurred even in the presence of the Trk inhibitor K252a. The release caused by NGF but not brain-derived neurotrophic factor was enhanced in neurons overexpressing p75. Further, after transfection of p75-small interfering RNA, which down-regulated the endogenous p75 expression, the NGF-induced release was inhibited, suggesting that the NGF-induced glutamate release was through p75. We found that the NGF-increased Ca2+ was derived from the ryanodine-sensitive Ca2+ receptor and that the NGF-increased Ca2+ was essential for the NGF-induced glutamate release. Furthermore, scyphostatin, a sphingomyelinase inhibitor, blocked the NGF-dependent Ca2+ increase and glutamate release, suggesting that a ceramide produced by sphingomyelinase was required for the NGF-stimulated Ca2+ increase and glutamate release. This action of NGF only occurred in developing neurons whereas the brain-derived neurotrophic factor-mediated Ca2+ increase and glutamate release was observed at the mature neuronal stage. Thus, we demonstrate that NGF-mediated neurotransmitter release via the p75-dependent pathway has an important role in developing neurons.     

Inflammation and free radicals in tumor development and progression

Inflammation is thought to be one of the major contributors to carcinogenesis. Accumulated studies in this field revealed that free radicals produced by inflammatory cells not only cause direct damage to DNA but also exert indirect effects such as de-regulation of cell proliferation and apoptosis, stimulation of angiogenesis, and modification of gene/protein expressions and protein activities, all of which are a critical step toward carcinogenesis. Free radicals have also been reported to act as both initiator and promoter of carcinogenic process. Recent evidence shows that free radicals convert benign tumors to more malignant ones (i.e. tumor progression) leading to the final stage of carcinogenesis. This article reviews the current findings linking inflammation and cancer, and shed light on inflammatory cell-derived free radicals as major endogenous reactive substances for tumor development and progression.     

Dynamics of large wood at the watershed scale: a perspective on current research limits and future directions

Recent research has elucidated the positive ecological roles of large wood (LW) in fish-bearing channels. However, where logjams increase local flooding and bank erosion, LW has negative impacts on public safety and property protection. Although our understanding of reach-scale processes and patterns has increased dramatically in recent years, only a few studies have integrated this knowledge at the watershed scale. Here we review variations in LW dynamics along a gradient of watershed sizes. In small watersheds, a massive amount of LW, resulting from forest dynamics and hillslope processes, remains on the valley floor. These pieces may persist for several decades and are eventually transported during debris flows. In intermediate watersheds, LW is dominantly recruited by bank erosion from adjacent riparian areas. These pieces are continuously transported downstream with LW pieces that are supplied from the upstream watershed by floods because these channels have a greater width and depth than the length and diameter of the pieces, as well as a high stream power. This leads to fragmentation of the LW pieces, which increases their transportability. In large watersheds, LW pieces are frequently recruited at locations where the channel is adjacent to riparian forests. Floated LW pieces can accumulate along channels with wide floodplains. Storage in floodplains can lead to more rapid decay than in an anaerobic environment, resulting in the subsequent removal of LW pieces from the system. Our review presents a generalized view of LW processing at the watershed scale, and is relevant to ecosystem management, disaster prevention and the identification of knowledge gaps.