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One-aminonaphthalene is sorbed onto the Na-saturated smectite clays, montmorillonite and hectorite, by cation exchange. In the presence of Fe3+, either in the clay structure or on the clay surface, sorption is followed by the formation of a blue-colored complex, with the continuous disappearance of aminonaphthalene from solution and the clay surface. The rate of aminonaphthalene disappearance decreases as pH increases. With time, four major products that appear to be structural isomers of N(4-aminonaphthyl)-l-naphthylamine are produced. A simplified model of this transformation is suggested to be the oxidation by Fe3+ of sorbed aminonaphthalene forming a radical cation-clay complex. A subsequent reaction between the radical-cation and a neutral aminonaphthalene molecule takes place, with the products being strongly sorbed to the clay surface.
Former professional American football players have a high relative risk for neurodegenerative diseases like chronic traumatic encephalopathy (CTE). Interpreting low cognitive test scores in this population occasionally is complicated by performance on validity testing. Neuroimaging biomarkers may help inform whether a neurodegenerative disease is present in these situations. We report three cases of retired professional American football players who completed comprehensive neuropsychological testing, but “failed” performance validity tests, and underwent multimodal neuroimaging (structural MRI, Aß-PET, and tau-PET).
Participants and Methods:
Three cases were identified from the Focused Neuroimaging for the Neurodegenerative Disease Chronic Traumatic Encephalopathy (FIND-CTE) study, an ongoing multimodal imaging study of retired National Football League players with complaints of progressive cognitive decline conducted at Boston University and the UCSF Memory and Aging Center. Participants were relatively young (age range 55-65), had 16 or more years of education, and two identified as Black/African American. Raw neuropsychological test scores were converted to demographically-adjusted z-scores. Testing included standalone (Test of Memory Malingering; TOMM) and embedded (reliable digit span, RDS) performance validity measures. Validity cutoffs were TOMM Trial 2 < 45 and RDS < 7. Structural MRIs were interpreted by trained neurologists. Aß-PET with Florbetapir was used to quantify cortical Aß deposition as global Centiloids (0 = mean cortical signal for a young, cognitively normal, Aß negative individual in their 20s, 100 = mean cortical signal for a patient with mild-to-moderate Alzheimer’s disease dementia). Tau-PET was performed with MK-6240 and first quantified as standardized uptake value ratio (SUVR) map. The SUVR map was then converted to a w-score map representing signal intensity relative to a sample of demographically-matched healthy controls.
Results:
All performed in the average range on a word reading-based estimate of premorbid intellect. Contribution of Alzheimer’s disease pathology was ruled out in each case based on Centiloids quantifications < 0. All cases scored below cutoff on TOMM Trial 2 (Case #1=43, Case #2=42, Case #3=19) and Case #3 also scored well below RDS cutoff (2). Each case had multiple cognitive scores below expectations (z < -2.0) most consistently in memory, executive function, processing speed domains. For Case #1, MRI revealed mild atrophy in dorsal fronto-parietal and medial temporal lobe (MTL) regions and mild periventricular white matter disease. Tau-PET showed MTL tau burden modestly elevated relative to controls (regional w-score=0.59, 72nd%ile). For Case #2, MRI revealed cortical atrophy, mild hippocampal atrophy, and a microhemorrhage, with no evidence of meaningful tau-PET signal. For Case #3, MRI showed cortical atrophy and severe white matter disease, and tau-PET revealed significantly elevated MTL tau burden relative to controls (w-score=1.90, 97th%ile) as well as focal high signal in the dorsal frontal lobe (overall frontal region w-score=0.64, 74th%ile).
Conclusions:
Low scores on performance validity tests complicate the interpretation of the severity of cognitive deficits, but do not negate the presence of true cognitive impairment or an underlying neurodegenerative disease. In the rapidly developing era of biomarkers, neuroimaging tools can supplement neuropsychological testing to help inform whether cognitive or behavioral changes are related to a neurodegenerative disease.
This study integrated an experimental medicine approach and a randomized cross-over clinical trial design following CONSORT recommendations to evaluate a cognitive training (CT) intervention for attention deficit hyperactivity disorder (ADHD). The experimental medicine approach was adopted because of documented pathophysiological heterogeneity within the diagnosis of ADHD. The cross-over design was adopted to provide the intervention for all participants and make maximum use of data.
Methods
Children (n = 93, mean age 7.3 +/− 1.1 years) with or sub-threshold for ADHD were randomly assigned to CT exercises over 15 weeks, before or after 15 weeks of treatment-as-usual (TAU). Fifteen dropped out of the CT/TAU group and 12 out of the TAU/CT group, leaving 66 for cross-over analysis. Seven in the CT/TAU group completed CT before dropping out making 73 available for experimental medicine analyses. Attention, response inhibition, and working memory were assessed before and after CT and TAU.
Results
Children were more likely to improve with CT than TAU (27/66 v. 13/66, McNemar p = 0.02). Consistent with the experimental medicine hypotheses, responders improved on all tests of executive function (p = 0.009–0.01) while non-responders improved on none (p = 0.27–0.81). The degree of clinical improvement was predicted by baseline and change scores in focused attention and working memory (p = 0.008). The response rate was higher in inattentive and combined subtypes than hyperactive-impulsive subtype (p = 0.003).
Conclusions
Targeting cognitive dysfunction decreases clinical symptoms in proportion to improvement in cognition. Inattentive and combined subtypes were more likely to respond, consistent with targeted pathology and clinically relevant heterogeneity within ADHD.
Item 9 of the Patient Health Questionnaire-9 (PHQ-9) queries about thoughts of death and self-harm, but not suicidality. Although it is sometimes used to assess suicide risk, most positive responses are not associated with suicidality. The PHQ-8, which omits Item 9, is thus increasingly used in research. We assessed equivalency of total score correlations and the diagnostic accuracy to detect major depression of the PHQ-8 and PHQ-9.
Methods
We conducted an individual patient data meta-analysis. We fit bivariate random-effects models to assess diagnostic accuracy.
Results
16 742 participants (2097 major depression cases) from 54 studies were included. The correlation between PHQ-8 and PHQ-9 scores was 0.996 (95% confidence interval 0.996 to 0.996). The standard cutoff score of 10 for the PHQ-9 maximized sensitivity + specificity for the PHQ-8 among studies that used a semi-structured diagnostic interview reference standard (N = 27). At cutoff 10, the PHQ-8 was less sensitive by 0.02 (−0.06 to 0.00) and more specific by 0.01 (0.00 to 0.01) among those studies (N = 27), with similar results for studies that used other types of interviews (N = 27). For all 54 primary studies combined, across all cutoffs, the PHQ-8 was less sensitive than the PHQ-9 by 0.00 to 0.05 (0.03 at cutoff 10), and specificity was within 0.01 for all cutoffs (0.00 to 0.01).
Conclusions
PHQ-8 and PHQ-9 total scores were similar. Sensitivity may be minimally reduced with the PHQ-8, but specificity is similar.
Determining infectious cross-transmission events in healthcare settings involves manual surveillance of case clusters by infection control personnel, followed by strain typing of clinical/environmental isolates suspected in said clusters. Recent advances in genomic sequencing and cloud computing now allow for the rapid molecular typing of infecting isolates.
Objective:
To facilitate rapid recognition of transmission clusters, we aimed to assess infection control surveillance using whole-genome sequencing (WGS) of microbial pathogens to identify cross-transmission events for epidemiologic review.
Methods:
Clinical isolates of Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, and Klebsiella pneumoniae were obtained prospectively at an academic medical center, from September 1, 2016, to September 30, 2017. Isolate genomes were sequenced, followed by single-nucleotide variant analysis; a cloud-computing platform was used for whole-genome sequence analysis and cluster identification.
Results:
Most strains of the 4 studied pathogens were unrelated, and 34 potential transmission clusters were present. The characteristics of the potential clusters were complex and likely not identifiable by traditional surveillance alone. Notably, only 1 cluster had been suspected by routine manual surveillance.
Conclusions:
Our work supports the assertion that integration of genomic and clinical epidemiologic data can augment infection control surveillance for both the identification of cross-transmission events and the inclusion of missed and exclusion of misidentified outbreaks (ie, false alarms). The integration of clinical data is essential to prioritize suspect clusters for investigation, and for existing infections, a timely review of both the clinical and WGS results can hold promise to reduce HAIs. A richer understanding of cross-transmission events within healthcare settings will require the expansion of current surveillance approaches.
An animal egg such as amphibian, mammalian or sea urchin egg receives only a single sperm at fertilisation. After binding of the first sperm, the egg is prevented from allowing the entry of additional sperm. In fact, polyspermy results in aborted development of the zygote. It has been generally accepted that a molecule(s) released from cortical granules participates in the block to polyspermy. As one such molecule, a cortical granule lectin has been isolated from unfertilised Xenopus eggs (Xenopus cortical granule lectin; XCGL). XCGL is released into the perivitelline space after fertilisation, and forms a complex with J1 jelly molecules to form an F layer, resulting in a block to additional sperm penetration.
A lectin molecule has also been purified from the eggs of several species of fish. The fish egg lectin is located in the cortical alveoli and is released from them after fertilisation. However, its biological function is unclear. We isolated cortical alveolar lectin from unfertilised eggs of Chinook salmon through affinity column chromatography (salmon egg lectin; SEL). The lectin activity was estimated by haemagglutination. The activity of the purified SEL was most strongly inhibited by L-rhamnose and D-galactose, but not by EDTA. Further analysis by C4 reverse-phase column chromatography using HPLC revealed that the lectin was composed of three subunit proteins: 24K, 26Ka and 26Kb proteins. In addition, we cloned cDNAs for them by RT-PCR. The deduced amino acid sequence of the 26Ka protein was homologous with that of the 26Kb protein (identity, 96.4%). Identities of the 24K with the 26Ka and the 26Kb proteins were 55.9% and 66.7%, respectively. A database search revealed that a lectin molecule similar to the SEL had been identified in Anthocidaris crassispina egg (sea urchin egg lectin; SUEL). The SUEL is composed of 105 amino acids, and is similar to both amino-terminal and carboxyl-terminal halves of the SELs. Thus, the SEL molecule is composed of two repeats of such SUEL-like domains, suggesting that the SEL gene was produced by gene duplication.
Different diagnostic interviews are used as reference standards for major depression classification in research. Semi-structured interviews involve clinical judgement, whereas fully structured interviews are completely scripted. The Mini International Neuropsychiatric Interview (MINI), a brief fully structured interview, is also sometimes used. It is not known whether interview method is associated with probability of major depression classification.
Aims
To evaluate the association between interview method and odds of major depression classification, controlling for depressive symptom scores and participant characteristics.
Method
Data collected for an individual participant data meta-analysis of Patient Health Questionnaire-9 (PHQ-9) diagnostic accuracy were analysed and binomial generalised linear mixed models were fit.
Results
A total of 17 158 participants (2287 with major depression) from 57 primary studies were analysed. Among fully structured interviews, odds of major depression were higher for the MINI compared with the Composite International Diagnostic Interview (CIDI) (odds ratio (OR) = 2.10; 95% CI = 1.15–3.87). Compared with semi-structured interviews, fully structured interviews (MINI excluded) were non-significantly more likely to classify participants with low-level depressive symptoms (PHQ-9 scores ≤6) as having major depression (OR = 3.13; 95% CI = 0.98–10.00), similarly likely for moderate-level symptoms (PHQ-9 scores 7–15) (OR = 0.96; 95% CI = 0.56–1.66) and significantly less likely for high-level symptoms (PHQ-9 scores ≥16) (OR = 0.50; 95% CI = 0.26–0.97).
Conclusions
The MINI may identify more people as depressed than the CIDI, and semi-structured and fully structured interviews may not be interchangeable methods, but these results should be replicated.
Declaration of interest
Drs Jetté and Patten declare that they received a grant, outside the submitted work, from the Hotchkiss Brain Institute, which was jointly funded by the Institute and Pfizer. Pfizer was the original sponsor of the development of the PHQ-9, which is now in the public domain. Dr Chan is a steering committee member or consultant of Astra Zeneca, Bayer, Lilly, MSD and Pfizer. She has received sponsorships and honorarium for giving lectures and providing consultancy and her affiliated institution has received research grants from these companies. Dr Hegerl declares that within the past 3 years, he was an advisory board member for Lundbeck, Servier and Otsuka Pharma; a consultant for Bayer Pharma; and a speaker for Medice Arzneimittel, Novartis, and Roche Pharma, all outside the submitted work. Dr Inagaki declares that he has received grants from Novartis Pharma, lecture fees from Pfizer, Mochida, Shionogi, Sumitomo Dainippon Pharma, Daiichi-Sankyo, Meiji Seika and Takeda, and royalties from Nippon Hyoron Sha, Nanzando, Seiwa Shoten, Igaku-shoin and Technomics, all outside of the submitted work. Dr Yamada reports personal fees from Meiji Seika Pharma Co., Ltd., MSD K.K., Asahi Kasei Pharma Corporation, Seishin Shobo, Seiwa Shoten Co., Ltd., Igaku-shoin Ltd., Chugai Igakusha and Sentan Igakusha, all outside the submitted work. All other authors declare no competing interests. No funder had any role in the design and conduct of the study; collection, management, analysis and interpretation of the data; preparation, review or approval of the manuscript; and decision to submit the manuscript for publication.
Domesticated from a wild teosinte grass in southern Mexico more than 6,000 years ago, maize (Zea mays ssp. mays L.) is today the world's single most important food crop. In this chapter I follow the initial diffusion of this major domesticate from its origin north through Mexico into the southwestern United States and then across the southern Plains into eastern North America, and consider its evolution under human selection during its long journey. Maize provides a well-documented example of a domesticate that was not part of a crop complex carried into new regions by expanding agricultural societies, but rather was exchanged, unaccompanied by other domesticates, from group to group.
Keywords: Maize, domestication, North America, crop diffusion
INTRODUCTION
Domesticated from a wild teosinte grass in southern Mexico more than 6,000 years ago, maize (Zea mays ssp. mays L.) is today the world's single most important food crop, with a recent annual harvest of more than 818 million metric tons (Varshney et al. 2012: Table 1). In this chapter I look at the early history of this major crop and follow its initial diffusion northward through Mexico into the southwestern United States and then across the Great Plains into the eastern woodlands of North America. A general temporal framework for the spread of maize throughout the Americas now exists, based on direct small-sample accelerator mass spectrometry (AMS) radiocarbon dating of cob and kernel remains recovered from sites scattered across this vast geographical area (Blake 2006). While this general spatial-temporal map of maize diffusion is still very much a work in progress (see ancientmaize.com), it does bring into clearer focus a wide range of questions, many of which are still unanswered, regarding the rates, routes, and mechanisms of initial human diffusion of the domesticate, its evolution under human selection, its adaptation to new environments, and the wide range of different ways in which it was added into and eventually came to dominate the subsistence economies of small-scale societies throughout North America.
SOUTHERN MEXICO: THE START OF THE JOURNEY
Populations of a wild teosinte grass that grow today along the central Balsas River valley in southern Mexico (Zea mays ssp. parviglumis Iltis and Doebley) have been identified as being phylogenetically most closely allied with maize, and are considered to be the present-day descendants of its probable wild progenitor (Matsuoka et al. 2002).
Weed resistance to herbicides occurs when herbicides are overused and can be mitigated by reducing their use. Consensus on herbicide resistance management strategies is problematic given strong industrial profit motive links in the weed science discipline.
Concern over the consequences of increased weed seed inputs to the soil seed bank during the transition period from conventional to organic production is one obstacle to grower adoption of reduced input and nonchemical weed management strategies. An 11-yr study was established in southwest Montana to investigate the effect of a single pulse of wild oat seeds on subsequent seed bank dynamics. In 1993, wild oat seeds were sown at five densities (0, 20, 80, 320, and 800 seeds m−2) in eight wheat–small grain cropping systems that differed in the number of crops in rotation and fallow periods. Wild oat seed banks were measured each spring from 1994 to 2004 in half of the cropping systems and from 2001 to 2004 in all eight systems. In 1994, seed bank densities in response to the pulse were as much as 11 times higher than controls that received no seeds in 1993. By 1996, after mechanical fallowing of all cropping systems, wild oat seed bank densities were not significantly different from densities in control plots regardless of the size of the initial seed pulse and remained so through 2004. These data suggest that increases in wild oat seed inputs during the organic transition period will have relatively few long-term agronomic effects on the dynamics of wild oat seed banks in these systems. In addition, wild oat seed banks may be constrained by factors other than cropping sequence when herbicides are not used, such as possible density-dependent regulation as a result of increased soil pathogen attack and seed predation.
The dynamic model Nitrogen Dynamics in Crop rotations in Ecological Agriculture (NDICEA) was used to assess the nitrogen (N), phosphorus (P) and potassium (K) balance of long-term organic cropping trials and typical organic crop rotations on a range of soil types and rainfall zones in the UK. The measurements of soil N taken at each of the organic trial sites were also used to assess the performance of NDICEA. The modeled outputs compared well to recorded soil N levels, with relatively small error margins. NDICEA therefore seems to be a useful tool for UK organic farmers. The modeling of typical organic rotations has shown that positive N balances can be achieved, although negative N balances can occur under high rainfall conditions and on lighter soil types as a result of leaching. The analysis and modeling also showed that some organic cropping systems rely on imported sources of P and K to maintain an adequate balance and large deficits of both nutrients are apparent in stockless systems. Although the K deficits could be addressed through the buffering capacity of minerals, the amount available for crop uptake will depend on the type and amount of minerals present, current cropping and fertilization practices and the climatic environment. A P deficit represents a more fundamental problem for the maintenance of crop yields and the organic sector currently relies on mined sources of P which represents a fundamental conflict with the International Federation of Organic Agriculture Movements organic principles.
The search for novel anxiolytics and antidepressants has focused on compounds with the potential to reduce excessive hypothalamic-pituitary-adrenal (HPA) axis activity. L-glutamate, an excitatory neurotransmitter ubiquitously present within the central nervous system, conceivably plays an important role in activating the neural sites involved in stress modulation. Deactivation of the HPA axis by glutamatergic neurotransmission modulation may represent a novel therapeutic approach. Accordingly, the acute intravenous effects of the novel metabotropic (mGlu2/3) agonist LY354740 were tested on bonnet macaques (Macaca radiata) undergoing acute infusions of yohimbine, a noradrenergic stimulant. Dependent measures were the magnitude of the increase of plasma cortisol and plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) customarily elicited by yohimbine. Next, the effects of 6 weeks of chronic oral administration of LY354740 on baseline (postcapture) plasma cortisol and MHPG levels in comparison to the identical measure in untreated controls were assessed. Subjects chronically treated with LY354740 received yohimbine infusions which were compared to yohimbine infusions and saline infusions in non-LY354740-treated subjects. Preliminary evidence supports the view that acute LY354740 infusion resulted in a marked diminution of yohimbine-induced stress response, as manifest by a substantial attenuation of cortisol and MHPG response observed in comparison to the saline-treated yohimbine condition. Chronic oral administration of LY354740 led to postcapture baseline cortisol levels which were markedly reduced (∼50%) in comparison to untreated control subjects; however, there were no significant parallel differences in MHPG levels. Yohimbine infusions elicited an increase in cortisol and MHPG levels in both LY354740-treated and non-LY354740-treated subjects, in comparison to declines in cortisol values observed following vehicle infusions (group X time interaction; P<.0001). Chronic LY354740-treated subjects failed to achieve cortisol levels comparable in range to those of untreated subjects primarily because of their low baseline cortisol levels. In contrast, despite equivalent baselines, yohimbine-induced MHPG values were increased overall in the chronically treated group compared to the saline and yohimbine-alone groups. Thus, LY354740 markedly reduced the acute corticoid and noradrenergic response elicited by yohimbine infusion. Chronic administration of LY354740 appears to present a safe and effective mechanism to markedly down-modulate the HPA axis while retaining noradrenergic responsivity.
Communication between emergency department (ED) staff and parents of children with asthma may play a role in asthma exacerbation management. We investigated the extent to which parents of children with asthma implement recommendations provided by the ED staff. Method: We asked questions on asthma triggers, ED care (including education and discharge recommendations), and asthma management strategies used at home shortly after the ED visit and again at 6 months.
Results:
A total of 148 children with asthma were recruited. Thirty-two percent of children were not on inhaled corticosteroids prior to their ED visit. Eighty percent of parents identified upper respiratory tract infections (URTIs) as the primary trigger for their child’s asthma. No parent received or implemented any specific asthma strategies to reduce the impact of URTIs; 82% of parents did not receive any printed asthma education materials. Most (66%) parents received verbal instructions on how to manage their child’s future asthma exacerbations. Of those, one-third of families were told to return to the ED. Parents were rarely advised to bring their child to their family doctor in the event of a future exacerbation. At 6 months, parents continued to use the ED services for asthma exacerbations in their children, despite reporting feeling confident in managing their child’s asthma.
Conclusion:
Improvements are urgently needed in developing strategies to manage pediatric asthma exacerbations related to URTIs, communication with parents at discharge in acute care, and using alternate acute care services for parents who continue to rely on EDs for the initial care of mild asthma exacerbations.