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result(s) for
"Halm, Robert"
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Initial clusters in pre-Proto-Nivkh: Internal reconstruction from Proto-Nivkh
Building on recent work towards the reconstruction of Proto- and pre-Proto-Nivkh (Fortescue, 2016; Janhunen, 2016; Halm, 2017; Halm & Slater, 2018), we use internal reconstruction to investigate two developments (probably regular sound changes) of initial consonant clusters in pre-Proto-Nivkh, taking rigorously reconstructable Proto-Nivkh forms as our point of departure. These developments are: (1) the surface-level loss of an original manner contrast (perhaps plosive-versus-fricative) in oral obstruents in cluster-second position, leaving only a morphophonemic contrast (between obstruents which show a predictable plosive-fricative alternation under prefixation and those which remain fricatives invariantly) as its reflex; and much more tentatively, (2) the deletion of original palatal glides in syllable onsets originally containing any consonant cluster.
Journal Article
Application of the comparative method to vocoid sequences in Nivkh
The Nivkh language family of Sakhalin Island and the adjacent mainland in Northeast Asia is generally considered to be without known external relatives. Since its internal diversity is relatively shallow – leading some authors to treat it as a single ‘language’ divisible only into ‘dialect’-level varieties – comparative linguistics internal to the family has been neglected. The internal diversity of Nivkh is not, however, as trivial as has been portrayed, and involves at least two (Gruzdeva, 1998) and possibly three Fortescue (2016) mutually unintelligible varieties, indicating fertile ground for the application of the Standard Comparative Method within the family. In the present paper, the correspondences of vocoid sequences among six attested varieties are examined, allowing an important sound change affecting one major variety group (Proto-Nivkh /*a, *i, *u/ > Amur Nivkh, West Sakhalin Nivkh, and North Sakhalin Nivkh /@/ when followed by a glide) to be reconstructed, as well as the applicable environment for this change to be precisely circumscribed, and furthermore allowing for an important phonological contrast for the proto-language to be reconstructed which is not well documented in the living varieties; namely, a contrast between sequences of vowel-glide and similar diphthongs, /*aw, *iw, *aj, *uj/ ̸= /*au, *iu, *ai, *ui/.
Journal Article
Application of the comparative method to Nivkh: Other regular sound correspondences
The Nivkh language family of Sakhalin Island and the adjacent mainland in Northeast Asia is generally considered to be without known external relatives, and since its internal diversity is relatively shallow— leading some authors to treat it as a single ‘language’ divisible only into ‘dialect’-level varieties—comparative linguistics internal to the family has been neglected. The internal diversity of Nivkh is not, however, as trivial as has been portrayed, and involves at least two (Gruzdeva, 1998) and possibly three (Fortescue, 2016) mutually unintelligible varieties, indicating fertile ground for the application of the Standard Comparative Method within the family. Following up on our previous work (Halm, 2017), in which we examined the synchronic sound correspondences and diachronic sound changes pertaining to vocoid sequences, in the present paper we adduce and examine other sound correspondences and attempt to define their underlying diachronic developments. Our clearest findings include: Proto-Nivkh (PN) /*a/ > Amur Nivkh (AN), West Sakhalin Nivkh (WSN), and perhaps North Sakhalin Nivkh (NSN) /ǝ/ when adjacent to or tautosyllabic with a velar consonant and not prohibited by vowel harmony or similar adjacency to a post-velar consonant; PN /*i/ > AN, WSN /ǝ/ | /[t,d]__+/; PN /*mx, *mχ/ > AN, WSN /ŋk/; PN /*ŋq/ > AN, WSN /ŋk/ morphemefinally, and probably in all positions; PN /*χ/ > AN, WSN /x/ | /o(C)__/; PN clusters of a palatal and an alveolar consonant generally assimilate to alveolar articulation for both segments, both historically and synchronically, in East Sakhalin Nivkh (ESN) and South Sakhalin Nivkh (SSN); morpheme-initial clusters with a lenis PN initial consonant are shifted to fortis articulation in SSN; PN velar fricatives /*x/ > Nogliki Nivkh (NgN), SSN /χ/ when preceded in a cluster by /c(h), t(h)/ (with some other conditioning differing between NgN and SSN); and finally, we confirm some sound changes already observed individually in the literature, and refute or question others. We also briefly discuss the phylogeny of the attested varieties in light of shared historical sound changes.
Journal Article
ACTIVE POTASSIUM TRANSPORT ACROSS THE ISOLATED TURTLE COLON
Although evidence has been obtained for active epithelial K transport, the cellular mechanisms responsible are not well understood. Progress in the study of epithelial K transport has been hindered by two problems: (1) the lack of a convenient model system in which K transport can be studied under conditions where the transepithelial driving forces can be readily controlled, (2) the inherent difficulties in discerning the contributions of the apical and basolateral membranes to transepithelial ion transport. The object of this study was to investigate the mechanisms of K transport in a simple epithelium, the colon of the freshwater turtle, which can be conveniently isolated from the animal, stripped of muscle and mounted as a flat sheet so that transepithelial electrochemical gradients can be readily controlled. The results clearly demonstrate that the turtle colon is capable of both active absorption and active secretion of K. A working hypothesis for active K transport was tested by examining the effect of ouabain and barium on K fluxes. In the turtle colon, K absorption was inhibited by mucosal ouabain and serosal barium. These observations support the concept of active apical K uptake, mediated by the Na:K ATPase, and conductive basolateral exit, via the barium-sensitive basolateral K channel. Potassium secretion was inhibited by serosal ouabain and mucosal barium which is consistant with K secretion driven by the basolateral Na:K pump, and passive apical exit via an apical K channel. A paracellular pathway exists in parallel with the cellular pathway for K flow. The selectivity of this pathway for K and Na is consistant with diffusion through a simple aqueous region. If a Na:K pump drives net Na absorption and K secretion, then an increase in pump rate should increase both ion flows. An increase in Na absorption, by increasing mucosal Na concentration, did not increase K secretion in the short-circuit state, but under open-circuit conditions K secretion was usually increased. These results demonstrate that the transcellular flows of K and Na, produced by active basolateral exchange of Na and K, can be dissociated such that independent regulation of Na absorption and K secretion is possible.
Dissertation
Safety and efficacy of percutaneous transabdominal and transesophageal decompression gastric catheters for palliation of malignant bowel obstruction
PurposeTo evaluate the safety and primary technical success rate of gastric decompression via percutaneous transabdominal gastrostomy (PTAG) or percutaneous transesophageal gastric (PTEG) catheter placement for management of malignant bowel obstruction (MBO). A secondary purpose was to evaluate the safety and success rate for PTAG catheter placement in patients with both MBO and ascites.MethodsA single-institution retrospective review of 385 patients who underwent attempted decompression gastric catheter placement from March 2013 to August 2018 was performed. Medical records and imaging studies were reviewed. A subgroup of patients with concomitant MBO and ascites were identified. The primary outcome measures were procedural technical success and procedural complications.Results394 decompression gastrostomy catheters were attempted from 2013 to 2018, n = 353 PTAG and n = 41 PTEG. The success rate was 95.5% (n = 337 of 353) for PTAG and 97.6% (n = 40 of 41) for PTEG. There were 63 total complications involving 47 (13.9%) patients following PTAG and 13 total complications involving 9 (22.5%) patients following PTEG, P = 0.16. For the subgroup of patients with MBO and ascites, the success rate was 94.8% (n = 182 of 192 patients), and there were 20 complications involving 17 (12.9%) of 132 patients.ConclusionGastric decompression for patients with MBO via PTAG or PTEG catheter placement is associated with high success rates and low complications.
Journal Article
Adjunctive hyperbaric oxygen therapy in the management of severe lower limb soft tissue injuries: a systematic review
Purpose
Traumatic crush injuries of the lower limb often accompany severe complications. The incorporation of hyperbaric oxygen therapy to standard trauma care may have the potential to diminish injury-related complications and improve outcome in such cases. This systematic review aims to evaluate the effectiveness of hyperbaric oxygen therapy in the management of severe lower limb soft tissue injuries.
Methods
The electronic databases Medline, Embase and Cochrane Library were searched to identify studies involving patients with crush-associated sever lower limb soft tissue injuries who received hyperbaric oxygen therapy in conjunction with standard trauma care. Relevant data on type of injury, hyperbaric oxygen therapy protocol and outcome related to wound healing were extracted.
Results
In total seven studies met the inclusion criteria, involving 229 patients. The studies included two randomized clinical trials, one retrospective cohort study, three case series and one case report. The randomized placebo-controlled clinical trial showed a significant increase in wound healing and decrease in the need for additional surgical interventions in the patient group receiving hyperbaric oxygen therapy when compared to those undergoing sham therapy. The randomized non-placebo-controlled clinical trial revealed that early hyperbaric oxygen therapy reduces tissue necrosis and the likelihood of long-term complications. The retrospective cohort study indicated that hyperbaric oxygen therapy effectively reduces infection rates and the need for additional surgical interventions. The case series and case report presented beneficial results with regard to wound healing when hyperbaric oxygen therapy was added to the treatment regimen.
Conclusion
Hyperbaric oxygen therapy is generally considered a safe therapeutic intervention and seems to have a beneficial effect on wound healing in severe lower limb soft tissue injuries when implemented as an addition to standard trauma care.
Journal Article
Do Statins Increase the Risk of Esophageal Conditions? Findings from Four Propensity Score-Matched Analyses
Background and Objective
Statins are commonly used medications. Whereas some observational studies suggested an association of statin use with Barrett’s esophagus and some upper gastrointestinal symptoms, there is a dearth of data on the association of statins and common esophageal conditions such as gastroesophageal reflux disease and esophagitis. The aim of this study is to examine the association of statins with esophageal conditions.
Methods
This is a retrospective cohort study using regional military healthcare data (1 October, 2003 to 1 March, 2012). The primary analyses evaluated the odds of: esophagitis; symptoms of esophagitis; gastroesophageal reflux disease/dyspepsia; and esophageal complications of gastroesophageal reflux disease in four propensity score-matched cohorts of statin users and non-users (propensity score-overall, propensity score-healthy, propensity score-women, and propensity score-men cohorts). Secondary and sensitivity analyses were performed.
Results
In the propensity score-overall cohort (
n
= 12,684), statin users were more likely to be diagnosed with esophagitis (odds ratio 1.11, 95% confidence interval 1.01–1.22) and gastroesophageal reflux disease/dyspepsia (odds ratio 1.18, 95% confidence interval 1.10–1.27) compared with non-users. Similar findings were seen in the propensity score-healthy cohort and in the propensity score-men cohort. In the propensity score-women cohort, the odds of esophagitis was higher among statin users compared with non-users (odds ratio 1.16, 95% confidence interval 1.02–1.32) but other outcomes were not different. In sensitivity analyses, which excluded patients with obesity, statin use was not associated with an increased odds ratio of gastroesophageal reflux disease/dyspepsia.
Conclusion
Statin therapy was associated with higher odds of being diagnosed with esophagitis and gastroesophageal reflux disease/dyspepsia. Further study is warranted to elucidate the potential role of statins in these commonly diagnosed esophageal conditions.
Journal Article
γ-H2AX foci are increased in lymphocytes in vivo in young children 1 h after very low-dose X-irradiation: a pilot study
Background
Computed tomography (CT) is an imaging modality involving ionizing radiation. The presence of γ-H2AX foci after low to moderate ionizing radiation exposure has been demonstrated; however it is unknown whether very low ionizing radiation exposure doses from CT exams can induce γ-H2AX formation in vivo in young children.
Objective
To test whether very low ionizing radiation doses from CT exams can induce lymphocytic γ-H2AX foci (phosphorylated histones used as a marker of DNA damage) formation in vivo in young children.
Materials and methods
Parents of participating children signed a consent form. Blood samples from three children (ages 3–21 months) undergoing CT exams involving very low blood ionizing radiation exposure doses (blood doses of 0.22–1.22 mGy) were collected immediately before and 1 h post CT exams. Isolated lymphocytes were quantified for γ-H2AX foci by a technician blinded to the radiation status and dose of the patients. Paired
t
-tests and regression analyses were performed with significance levels set at
P
< 0.05.
Results
We observed a dose-dependent increase in γ-H2AX foci post-CT exams (
P
= 0.046) among the three children. Ionizing radiation exposure doses led to a linear increase of foci per cell in post-CT samples (102% between lowest and highest dose).
Conclusion
We found a significant induction of γ-H2AX foci in lymphocytes from post-CT samples of three very young children. When possible, CT exams should be limited or avoided by possibly applying non-ionizing radiation exposure techniques such as US or MRI.
Journal Article
Small molecule activators of sirtuins extend Saccharomyces cerevisiae lifespan
In diverse organisms, calorie restriction slows the pace of ageing and increases maximum lifespan. In the budding yeast
Saccharomyces cerevisia
e, calorie restriction extends lifespan by increasing the activity of Sir2 (ref.
1
), a member of the conserved sirtuin family of NAD
+
-dependent protein deacetylases
2
,
3
,
4
,
5
,
6
. Included in this family are SIR-2.1, a
Caenorhabditis elegans
enzyme that regulates lifespan
7
, and SIRT1, a human deacetylase that promotes cell survival by negatively regulating the p53 tumour suppressor
8
,
9
,
10
. Here we report the discovery of three classes of small molecules that activate sirtuins. We show that the potent activator resveratrol, a polyphenol found in red wine, lowers the Michaelis constant of SIRT1 for both the acetylated substrate and NAD
+
, and increases cell survival by stimulating SIRT1-dependent deacetylation of p53. In yeast, resveratrol mimics calorie restriction by stimulating Sir2, increasing DNA stability and extending lifespan by 70%. We discuss possible evolutionary origins of this phenomenon and suggest new lines of research into the therapeutic use of sirtuin activators.
Journal Article