bluuebunny/crossref_metadata_2025 huggingface dataset:
Profiling the Interest of General Dental Practitioners in West Yorkshire in using Teledentistry to Obtain Advice from Orthodontic Consultants
Authors: Bradley Sean M , Williams Sonia , D'Cruz Jini , Vania Ahmed
Published: July 2007

Objective

To seek opinions from general dental practitioners in Calderdale and Kirklees (West Yorkshire) regarding an online orthodontic referral service and to establish the profile of dentists working in primary care who would refer patients online for a consultant orthodontist's opinion.

Methodology

All 91 general dental practices in Calderdale and Kirklees in West Yorkshire were sent a piloted questionnaire enquiring into their orthodontic treatment and referral patterns, and also into their attitudes to the use of the Internet and related technologies. Three mailings were performed, followed by telephone contact with non-responders.

Results

Usable responses were obtained from 119 general dental practitioners who worked in 71 practices (78%). Analysis of data showed that, when asked whether they would be interested in using teledentistry to obtain a consultant orthodontist's opinion online, 53/116 (46%) replied positively. The most frequently specified reason for this interest was that it would save time and would achieve a quicker opinion for a practitioner's treatment plan. These dentists were more likely to be familiar with the use of digital cameras, be using removable appliances, and currently be in the habit of referring orthodontic cases to consultants and specialists.

Conclusions

Just under half of the dentists working in primary care in Calderdale and Kirklees who responded had a positive attitude towards the benefits of a teledentistry referral scheme. However, a substantial number remained undecided, possibly because they were unsure of their information technology (IT) skills. A further pilot study is planned. It will enquire into the feasibility of carrying out such an exercise across West Yorkshire.
Inequalities in the Provision of NHS Primary Care Dental Services in Scotland in 2004
Authors: Newton J Timothy , Williams Alison C , Bower Elizabeth J
Published: July 2007

Objective

To assess inequalities in the provision of National Health Service (NHS) primary care dental services between Health Boards and the four provider groups (General Dental Service [GDS] non-specialist, GDS salaried, specialist working in primary care, Community Dental Service [CDS]) in Scotland.

Methods

A postal questionnaire survey of all dentists (N=2852) registered with the General Dental Council at an address in Scotland was undertaken. The following were assessed: the proportion of primary care dentists not accepting new children/adults for NHS care or using a waiting list, the proportion of dentists working in wheelchair-accessible surgeries, furthest distance travelled by patients to primary care surgery in an average week, waiting time for routine NHS treatment, and the proportion of dentists offering weekend or evening appointments to NHS patients. Data were analysed by Health Board and the four provider groups.

Results

A total of 2134 (74.8%) completed questionnaires were returned. One thousand, five hundred and seventy-seven dentists (73.9%) of the respondents were providing NHS primary care dental services for at least part of each week. There was a wide variation in the provision of NHS primary care dental services between Health Boards. Borders, Dumfries and Galloway, and Grampian performed poorly on most indicators, whereas Lanarkshire, Greater Glasgow, and Argyll and Clyde generally performed well. The CDS scored well on most indicators of service provision. There were problems with the provision of specialist dental services in primary care, and GDS services provided by Health Boards.

Conclusions

Because the problem issues differed between Health Boards and the four provider groups, it is likely that both local and national solutions are required to improve the provision of services. Further research on service demand is required to confirm the apparent inequalities in provision suggested by the study.
Naproxen versus Acetaminophen for Therapy of Soft Tissue Injuries to the Ankle in Children
Authors: Cukiernik Victoria A , Lim Rod , Warren David , Seabrook Jamie A , Matsui Doreen , Rieder Michael J
Published: July 2007

Background:

Musculoskeletal (MSK) ankle injuries cause significant morbidity in ambulatory pediatric populations. No optimal pharmacotherapy is available.

Objective:

To conduct a randomized, double-blind trial to compare 2 drug therapies for soft tissue injury of the ankle.

Methods:

Patients (N = 77, aged 8–14 y, 61% male) with ankle injuries presenting to a regional pediatric emergency department were assigned to receive either acetaminophen (15 mg/kg 4 times a day) or naproxen (5 mg/kg 4 times a day) in a double-blind fashion on a routine basis for a 5 day period. On days 0 and 7, patients rated their degree of disability and pain on weight bearing using a 10 cm visual analog scale developed for this study. In addition, they were examined by a physician who rated pain, tenderness on palpation, and swelling using a 4 point scale. There were 3 follow-up telephone calls on days 3, 14, and 21. Adherence was evaluated by self-report and pill count.

Results:

Both the acetaminophen and naproxen groups had significant improvement in degree of disability and pain from day 0 to day 7. There was no statistically significant difference in outcome between the 2 groups by patient self-evaluation or physician assessment. There also was no significant difference in adverse event rates between the 2 groups, and the majority of patients in both groups felt that the medication was helpful.

Conclusions:

No significant difference in efficacy of pain control or improvement of disability between the naproxen and acetaminophen groups suggests no preferential advantage for naproxen over acetaminophen for MSK injuries when given on a regular basis, with concurrent supportive treatment. Possible differential benefit from intermittent therapy needs to be evaluated among children with ankle injury.
Polymorphisms within the Protein Tyrosine Phosphatase 1B (PTPN1) Gene Promoter: Functional Characterization and Association with Type 2 Diabetes and Related Metabolic Traits
Authors: Meshkani Reza , Taghikhani Mohammad , Al-Kateb Hussam , Larijani Bagher , Khatami Shohreh , Sidiropoulos Gus Konstantinos , Hegele Robert Alexander , Adeli Khosrow
Published: July 2007

Background: Protein tyrosine phosphatase 1B (PTPN1) dephosphorylates insulin receptors and attenuates insulin signaling. Polymorphisms in the coding sequence of PTPN1 have been variably associated with type 2 diabetes (T2D). We hypothesized that variations within the PTPN1 promoter might contribute to the development of T2D and related metabolic traits.

Methods: We screened 2.0 kb of PTPN1 promoter in 174 T2D patients and 412 controls using PCR and denaturing HPLC. Association analysis was performed between diabetes and related traits and single-nucleotide polymorphism genotypes. We functionally tested 2 variants (−1023C>A and −51delA) by measuring their influence on luciferase activity in HepG2 cells and performing the electrophoretic mobility shift assay (EMSA).

Results: One common (−1023C>A) and 6 rare (−51delA, −451A>G, −467T>C, −1045G>A, −1286-3bp-del, and −1291-9bp-del) variants were identified in the PTPN1 promoter. The −1023(C) allele had significant association with T2D that disappeared after we adjusted for established diabetes risk factors. The alleles of −1023C>A and −51delA variants did not show significant effects on the biochemical markers after adjustment for established diabetes risk factors in the nondiabetic and diabetic groups separately. The −51delA variant decreased luciferase gene expression in HepG2 cells by 2-fold. EMSA revealed a weaker binding of −51delA to specific protein family proteins compared with the A allele. The −1023C>A variant had no influence in either experiment.

Conclusions: The PTPN1 promoter variants −1023C>A and −51delA (which appears to be functional) were not associated with T2D or related traits in this study but must be investigated in a larger population to reveal any potential metabolic association.
Evidence of a Tonotopic Organization of the Auditory Cortex in Cochlear Implant Users
Authors: Guiraud Jeanne , Besle Julien , Arnold Laure , Boyle Patrick , Giard Marie-Hélène , Bertrand Olivier , Norena Arnaud , Truy Eric , Collet Lionel
Published: July 2007

Deprivation from normal sensory input has been shown to alter tonotopic organization of the human auditory cortex. In this context, cochlear implant subjects provide an interesting model in that profound deafness is made partially reversible by the cochlear implant. In restoring afferent activity, cochlear implantation may also reverse some of the central changes related to deafness. The purpose of the present study was to address whether the auditory cortex of cochlear implant subjects is tonotopically organized. The subjects were thirteen adults with at least 3 months of cochlear implant experience. Auditory event-related potentials were recorded in response to electrical stimulation delivered at different intracochlear electrodes. Topographic analysis of the auditory N1 component (∼85 ms latency) showed that the locations on the scalp and the relative amplitudes of the positive/negative extrema differ according to the stimulated electrode, suggesting that distinct sets of neural sources are activated. Dipole modeling confirmed electrode-dependent orientations of these sources in temporal areas, which can be explained by nearby, but distinct sites of activation in the auditory cortex. Although the cortical organization in cochlear implant users is similar to the tonotopy found in normal-hearing subjects, some differences exist. Nevertheless, a correlation was found between the N1 peak amplitude indexing cortical tonotopy and the values given by the subjects for a pitch scaling task. Hence, the pattern of N1 variation likely reflects how frequencies are coded in the brain.
Aβ Oligomer-Mediated Long-Term Potentiation Impairment Involves Protein Phosphatase 1-Dependent Mechanisms
Authors: Knobloch Marlen , Farinelli Mélissa , Konietzko Uwe , Nitsch Roger M. , Mansuy Isabelle M.
Published: July 2007

Amyloid β (Aβ) oligomers are derived from proteolytic cleavage of amyloid precursor protein (APP) and can impair memory and hippocampal long-term potentiation (LTP)in vivoandin vitro. They are recognized as the primary neurotoxic agents in Alzheimer's disease. The mechanisms underlying such toxicity on synaptic functions are complex and not fully understood. Here, we provide the first evidence that these mechanisms involve protein phosphatase 1 (PP1). Using a novel transgenic mouse model expressing human APP with the Swedish and Arctic mutations that render Aβ more prone to form oligomers (arcAβ mice), we show that the LTP impairment induced by Aβ oligomers can be fully reversed by PP1 inhibitionin vitro. We further demonstrate that the genetic inhibition of endogenous PP1in vivoconfers resistance to Aβ oligomer-mediated toxicity and preserves LTP. Overall, these results reveal that PP1 is a key player in the mechanisms of AD pathology.
Pharmacological Imposition of Sleep Slows Cognitive Decline and Reverses Dysregulation of Circadian Gene Expression in a Transgenic Mouse Model of Huntington's Disease
Authors: Pallier Patrick N. , Maywood Elizabeth S. , Zheng Zhiguang , Chesham Johanna E. , Inyushkin Alexei N. , Dyball Richard , Hastings Michael H. , Jennifer Morton A.
Published: July 2007

Transgenic R6/2 mice carrying the Huntington's disease (HD) mutation show disrupted circadian rhythms that worsen as the disease progresses. By 15 weeks of age, their abnormal circadian behavior mirrors that seen in HD patients and is accompanied by dysregulated clock gene expression in the circadian pacemaker, the suprachiasmatic nucleus (SCN). We found, however, that the electrophysiological output of the SCN assayedin vitrowas normal. Furthermore, the endogenous rhythm of circadian gene expression, monitoredin vitroby luciferase imaging of organotypical SCN slices removed from mice with disintegrated behavioral rhythms, was also normal. We concluded that abnormal behavioral and molecular circadian rhythms observed in R6/2 micein vivoarise from dysfunction of brain circuitry afferent to the SCN, rather than from a primary deficiency within the pacemaker itself. Because circadian sleep disruption is deleterious to cognitive function, and cognitive decline is pronounced in R6/2 mice, we tested whether circadian and cognitive disturbances could be reversed by using a sedative drug to impose a daily cycle of sleep in R6/2 mice. Daily treatment with Alprazolam reversed the dysregulated expression ofPer2and alsoProk2, an output factor of the SCN that controls behavioral rhythms. It also markedly improved cognitive performance of R6/2 mice in a two-choice visual discrimination task. Together, our data show for the first time that treatments aimed at restoring circadian rhythms may not only slow the cognitive decline that is such a devastating feature of HD but may also improve other circadian gene-regulated functions that are impaired in this disease.
Behavioral Measurements of a Temporally Precise Motor Code for Birdsong
Authors: Glaze Christopher M. , Troyer Todd W.
Published: July 2007

There are conflicting data on the timescale for the representation of adult zebra finch song. Acoustic structure and perturbation studies suggest that song is divided into discrete vocal elements, or syllables, lasting 50–200 ms. However, recordings in premotor telencephalic nucleus HVC (used as proper name) and RA (robust nucleus of arcopallium) suggest that song is represented by sparse, fine-grained bursting on the 5–10 ms timescale. We previously found patterns of timing variability that distinguish individual syllables and repeat across multiple 500- to 1000-ms-long motifs (Glaze and Troyer, 2006). Here, we extend our methods to analyze whether this is attributable to a syllable-based code or representations on a finer timescale. We find evidence for the latter. First, identity-dependent timing is dominated by independent variability in notes, finer song segments that compose a syllable; for example, the length of a note is no more correlated with other notes in the same syllable than it is with notes in other syllables. For a subset of notes, clear modulation in spectral structure allowed for accurate timing measurements on the 5–10 ms timescale. Temporal independence holds at this scale as well: the length of an individual 5–10 ms song slice is correlated with the same slice repeated 500–1000 ms later, yet is independent of neighboring slices. We propose that such fine-grained, persistent changes in song tempo result from an interaction between slow modulatory factors and precisely timed, sparse bursting in HVC and RA.
Annonacin, a Natural Mitochondrial Complex I Inhibitor, Causes Tau Pathology in Cultured Neurons
Authors: Escobar-Khondiker Myriam , Höllerhage Matthias , Muriel Marie-Paule , Champy Pierre , Bach Antoine , Depienne Christel , Respondek Gesine , Yamada Elizabeth S. , Lannuzel Annie , Yagi Takao , Hirsch Etienne C. , Oertel Wolfgang H. , Jacob Ralf , Michel Patrick P. , Ruberg Merle , Höglinger Günter U.
Published: July 2007

A neurodegenerative tauopathy endemic to the Caribbean island of Guadeloupe has been associated with the consumption of anonaceous plants that contain acetogenins, potent lipophilic inhibitors of complex I of the mitochondrial respiratory chain. To test the hypothesis that annonacin, a prototypical acetogenin, contributes to the etiology of the disease, we investigated whether annonacin affects the cellular distribution of the protein tau. In primary cultures of rat striatal neurons treated for 48 h with annonacin, there was a concentration-dependent decrease in ATP levels, a redistribution of tau from the axons to the cell body, and cell death. Annonacin induced the retrograde transport of mitochondria, some of which had tau attached to their outer membrane. Taxol, a drug that displaces tau from microtubules, prevented the somatic redistribution of both mitochondria and tau but not cell death. Antioxidants, which scavenged the reactive oxygen species produced by complex I inhibition, did not affect either the redistribution of tau or cell death. Both were prevented, however, by forced expression of the NDI1 nicotinamide adenine dinucleotide (NADH)-quinone-oxidoreductase ofSaccharomyces cerevisiae, which can restore NADH oxidation in complex I-deficient mammalian cells and stimulation of energy production via anaerobic glycolysis. Consistently, other ATP-depleting neurotoxins (1-methyl-4-phenylpyridinium, 3-nitropropionic, and carbonyl cyanidem-chlorophenylhydrazone) reproduced the somatic redistribution of tau, whereas toxins that did not decrease ATP levels did not cause the redistribution of tau. Therefore, the annonacin-induced ATP depletion causes the retrograde transport of mitochondria to the cell soma and induces changes in the intracellular distribution of tau in a way that shares characteristics with some neurodegenerative diseases.
Minocycline Alleviates Death of Oligodendrocytes by Inhibiting Pro-Nerve Growth Factor Production in Microglia after Spinal Cord Injury
Authors: Yune Tae Y. , Lee Jee Y. , Jung Gil Y. , Kim Sun J. , Jiang Mei H. , Kim Young C. , Oh Young J. , Markelonis George J. , Oh Tae H.
Published: July 2007

Spinal cord injury (SCI) causes a permanent neurological disability, and no satisfactory treatment is currently available. After SCI, pro-nerve growth factor (proNGF) is known to play a pivotal role in apoptosis of oligodendrocytes, but the cell types producing proNGF and the signaling pathways involved in proNGF production are primarily unknown. Here, we show that minocycline improves functional recovery after SCI in part by reducing apoptosis of oligodendrocytes via inhibition of proNGF production in microglia. After SCI, the stress-responsive p38 mitogen-activated protein kinase (p38MAPK) was activated only in microglia, and proNGF was produced by microglia via the p38MAPK-mediated pathway. Minocycline treatment significantly reduced proNGF production in microgliain vitroandin vivoby inhibition of the phosphorylation of p38MAPK. Furthermore, minocycline treatment inhibited p75 neurotrophin receptor expression and RhoA activation after injury. Finally, minocycline treatment inhibited oligodendrocyte death and improved functional recovery after SCI. These results suggest that minocycline may represent a potential therapeutic agent for acute SCI in humans.
Transient Overexpression of Striatal D2Receptors Impairs Operant Motivation and Interval Timing
Authors: Drew Michael R. , Simpson Eleanor H. , Kellendonk Christoph , Herzberg William G. , Lipatova Olga , Fairhurst Stephen , Kandel Eric R. , Malapani Chara , Balsam Peter D.
Published: July 2007

The striatum receives prominent dopaminergic innervation that is integral to appetitive learning, performance, and motivation. Signaling through the dopamine D2receptor is critical for all of these processes. For instance, drugs with high affinity for the D2receptor potently alter timing of operant responses and modulate motivation. Recently, in an attempt to model a genetic abnormality encountered in schizophrenia, mice were generated that reversibly overexpress D2receptors specifically in the striatum (Kellendonk et al., 2006). These mice have impairments in working memory and behavioral flexibility, components of the cognitive symptoms of schizophrenia, that are not rescued when D2overexpression is reversed in the adult. Here we report that overexpression of striatal D2receptors also profoundly affects operant performance, a potential index of negative symptoms. Mice overexpressing D2exhibited impairments in the ability to time food rewards in an operant interval timing task and reduced motivation to lever press for food reward in both the operant timing task and a progressive ratio schedule of reinforcement. The motivational deficit, but not the timing deficit, was rescued in adult mice by reversing D2overexpression with doxycycline. These results suggest that early D2overexpression alters the organization of interval timing circuits and confirms that striatal D2signaling in the adult regulates motivational process. Moreover, overexpression of D2under pathological conditions such as schizophrenia and Parkinson's disease could give rise to motivational and timing deficits.
Physiologically Distinct Temporal Cohorts of Cortical Interneurons Arise from TelencephalicOlig2-Expressing Precursors
Authors: Miyoshi Goichi , Butt Simon J. B. , Takebayashi Hirohide , Fishell Gord
Published: July 2007

Inhibitory GABAergic interneurons of the mouse neocortex are a highly heterogeneous population of neurons that originate from the ventral telencephalon and migrate tangentially up into the developing cortical plate. The majority of cortical interneurons arise from a transient embryonic structure known as the medial ganglionic eminence (MGE), but how the remarkable diversity is specified in this region is not known. We have taken a genetic fate mapping strategy to elucidate the temporal origins of cortical interneuron subtypes within the MGE. We used an inducible form of Cre under the regulation ofOlig2, a basic helix-loop-helix transcription factor highly expressed in neural progenitors of the MGE. We observe that the physiological subtypes of cortical interneurons are, to a large degree, unique to their time point of generation.
When bivalves took over the world
Authors: Fraiser Margaret L. , Bottjer David J.
Published: July 2007

The end-Permian mass extinction is commonly portrayed not only as a massive biodiversity crisis but also as the time when marine benthic faunas changed from the Paleozoic Fauna, dominated by rhynchonelliform brachiopod taxa, to the Modern Fauna, dominated by gastropod and bivalve taxa. After the end-Permian mass extinction, scenarios involving the Mesozoic Marine Revolution portray a steady increase in numerical dominance by these benthic molluscs as largely due to the evolutionary effects of an “arms race.” We report here a new global paleoecological database from study of shell beds that shows a dramatic geologically sudden earliest Triassic takeover by bivalves as numerical dominants in level-bottom benthic marine communities, which continued through the Early Triassic. Three bivalve genera were responsible for this switch, none of which has any particular morphological features to distinguish it from many typical Paleozoic bivalve genera. The numerical success of these Early Triassic bivalves cannot be attributed to any of the well-known morphological evolutionary innovations of post-Paleozoic bivalves that characterize the Mesozoic Marine Revolution. Rather, their ability to mount this takeover most likely was due to the large extinction of rhynchonelliform brachiopods during the end-Permian mass extinction and aided by their environmental distribution and physiological characteristics that enabled them to thrive during periods of oceanic and atmospheric stress during the Permian/Triassic transition.
Geographic variation in turnover and recovery from the Late Ordovician mass extinction
Authors: Krug Andrew Z. , Patzkowsky Mark E.
Published: July 2007

Understanding what drives global diversity requires knowledge of the processes that control diversity and turnover at a variety of geographic and temporal scales. This is of particular importance in the study of mass extinctions, which have disproportionate effects on the global ecosystem and have been shown to vary geographically in extinction magnitude and rate of recovery.

Here, we analyze regional diversity and turnover patterns for the paleocontinents of Laurentia, Baltica, and Avalonia spanning the Late Ordovician mass extinction and Early Silurian recovery. Using a database of genus occurrences for inarticulate and articulate brachiopods, bivalves, anthozoans, and trilobites, we show that sampling-standardized diversity trends differ for the three regions. Diversity rebounded to pre-extinction levels within 5 Myr in the paleocontinent of Laurentia, compared with 15 Myr or longer for Baltica and Avalonia. This increased rate of recovery in Laurentia was due to both lower Late Ordovician extinction rates and higher Early Silurian origination rates relative to the other continents. Using brachiopod data, we dissected the Rhuddanian recovery into genus origination and invasion. This analysis revealed that standing diversity in the Rhuddanian consisted of a higher proportion of invading taxa in Laurentia than in either Baltica or Avalonia. Removing invading genera from diversity counts caused Rhuddanian diversity to fall in Laurentia. However, Laurentian diversity still rebounded to pre-extinction levels within 10 Myr of the extinction event, indicating that genus origination rates were also higher in Laurentia than in either Baltica or Avalonia. Though brachiopod diversity in Laurentia was lower than in the higher-latitude continents prior to the extinction, increased immigration and genus origination rates made it the most diverse continent following the extinction. Higher rates of origination in Laurentia may be explained by its large size, paleogeographic location, and vast epicontinental seas. It is possible that the tropical position of Laurentia buffered it somewhat from the intense climatic fluctuations associated with the extinction event, reducing extinction intensities and allowing for a more rapid rebound in this region. Hypotheses explaining the increased levels of invasion into Laurentia remain largely untested and require further scrutiny. Nevertheless, the Late Ordovician mass extinction joins the Late Permian and end-Cretaceous as global extinction events displaying an underlying spatial complexity.
The ecology of invasion: acquisition and loss of the siphonal canal in gastropods
Authors: Vermeij Geerat J.
Published: July 2007

Most evolutionary innovations—power-enhancing phenotypes previously absent in a lineage—have arisen multiple times within major clades. This repetition permits a comparative approach to ask how, where, when, in which clades, and under which circumstances adaptive innovations are acquired and secondarily lost. I use new and literature-based data on the phylogeny, functional morphology, and fossil record of gastropods to explore the acquisition and loss of the siphonal canal and its variations in gastropods. The siphonal indentation, canal, notch, or tube at the front end of the shell is associated in living gastropods with organs that detect chemical signals directionally and at a distance in an anteriorly restricted inhalant stream of water.

Conservative estimates indicate that the siphonate condition arose 23 times and was secondarily lost 17 times. Four siphonate clades have undergone prodigious diversification. All siphonate gastropods have a shell whose axis of coiling lies at a low angle above the plane of the aperture (retroaxial condition). In early gastropods, the siphonal canal was short and more or less confined to the apertural plane. Later (mainly Cretaceous and Cenozoic) variations include a dorsally deflected canal, a long canal, and a closed canal. The closed siphonal canal, in which the edges join to form a tube, arose 15 times, all in the adult stages of caenogastropods with determinate growth.

Gastropods in which the siphonate condition arose were mobile, bottom-dwelling, microphagous animals. Active predaceous habits became associated with the siphonate condition in the Mesozoic and Cenozoic Purpurinidae-Latrogastropoda clade. Loss of the siphonate condition is associated with nonmarine habits, miniaturization, and especially with a sedentary or slow-moving mode of life.

The siphonate condition arose seven times each during the early to middle Paleozoic, the late Paleozoic, and the early to middle Mesozoic, and only once each during the Late Cretaceous and Cenozoic. Well-adapted incumbents prevented most post-Jurassic clades from evolving a siphonal indentation and its associated organs. Dorsally deflected, long, and closed canals are known only from Cretaceous and Cenozoic marine gastropods, and represent improvements in sensation and passive armor.

In a discussion of contrasting ecologies of clades that gained and lost the siphonate condition, I argue that macroevolutionary trends in the comings and goings of innovations and clades must incorporate ecological and functional data. Acquisitions of energy-intensive, complex innovations that yield greater power have a greater effect on ecosystems, communities, and their resident clades than do reversals, which generally reflect energy savings.
LONG‐TERM CHANGES AND IMPACTS OF HYPOXIA IN DANISH COASTAL WATERS
Authors: Conley Daniel J. , Carstensen Jacob , Ærtebjerg Gunni , Christensen Peter Bondo , Dalsgaard Tage , Hansen Jørgen L. S. , Josefson Alf B.
Published: July 2007

A 38‐year record of bottom‐water dissolved oxygen concentrations in coastal marine ecosystems around Denmark (1965–2003) and a longer, partially reconstructed record of total nitrogen (TN) inputs (1900–2003) were assembled with the purpose of describing long‐term patterns in hypoxia and anoxia. In addition, interannual variations in bottom‐water oxygen concentrations were analyzed in relation to various explanatory variables (bottom temperature, wind speed, advective transport, TN loading). Reconstructed TN loads peaked in the 1980s, with a gradual decline to the present, commensurate with a legislated nutrient reduction strategy. Mean bottom‐water oxygen concentrations during summer have significantly declined in coastal marine ecosystems, decreasing substantially during the 1980s and were extremely variable thereafter. Despite decreasing TN loads, the worst hypoxic event ever recorded in open waters occurred in 2002. For estuaries and coastal areas, bottom‐water oxygen concentrations were best described by TN input from land and wind speed in July–September, explaining 52% of the interannual variation in concentrations. For open sea areas, bottom‐water oxygen concentrations were also modulated by TN input from land; however, additional significant variables included advective transport of water and Skagerrak surface‐water temperature and explained 49% of interannual variations in concentrations. Reductions in the number of benthic species and alpha diversity were significantly related to the duration of the 2002 hypoxic event. Gradual decreases in diversity measures (number of species and alpha diversity) over the first 2–4 weeks show that the benthic community undergoes significant changes before the duration of hypoxia is severe enough to cause the community to collapse. Enhanced sediment–water fluxes of NH4+ and PO43− occur with hypoxia, increasing nutrient concentrations in the water column and stimulating additional phytoplankton production. Repeated hypoxic events have changed the character of benthic communities and how organic matter is processed in sediments. Our data suggest that repeated hypoxic events lead to an increase in susceptibility of Danish waters to eutrophication and further hypoxia.
PHYTOPLANKTON BLOOM EFFECTS ON A GULF ESTUARY: WATER QUALITY CHANGES AND BIOLOGICAL RESPONSE
Authors: Livingston Robert J.
Published: July 2007

A long‐term (16‐year) study addressed the relationship of the trophic organization of a river‐dominated Gulf of Mexico estuary (Perdido River–Bay system) with interannual trends of freshwater input, nutrient loading, and biological controlling features. The purpose of this study was to determine the long‐term consequences of anthropogenic nutrient loading on a river estuarine system with an emphasis on the origin and impacts of a series of plankton blooms that were directly linked with nutrient loading to the Perdido drainage system. A multidisciplinary database was used to determine responses of plankton assemblages and associated coastal food webs to natural and anthropogenic nutrient loading. Orthophosphate and ammonia loading from a pulp mill into Elevenmile Creek and the bay generated a series of plankton blooms dominated by diatoms, raphidophytes, dinoflagellates, and cyanobacteria. Blooms followed species‐specific seasonal patterns. Interannual phytoplankton trends were associated with nutrient loading and rainfall cycles. Blue‐green algae blooms (Merismopedia tenuissima) in the receiving Elevenmile Creek were enhanced by drought conditions. There were statistical associations of reduced biological activity with the Merismopedia blooms. In the bay, initial diatom blooms were replaced by raphidophytes and dinoflagellates in time. Bloom effects on phytoplankton assemblages included initial reductions of species richness/diversity and direct/indirect replacement processes. Long‐term changes of plankton blooms indicated complex adaptive processes that led to nonlinear responses to nutrient loading and time‐based alterations of interspecific relationships. Blooms and related changes in phytoplankton composition were accompanied by loss of fish and invertebrate populations and altered food web processes. Raphidophyte (Heterosigma akashiwo) and dinoflagellate (Prorocentrum cordatum) blooms in the bay were statistically associated with reduced invertebrate and fish populations and disruptions of bay food webs. Reduced nutrient loading by the pulp mill resulted in diminished bay plankton blooms and partial recovery of infaunal macroinvertebrates. However, nutrient loading from a second source in the upper bay during later years was associated with increased bloom activity. This was added to reduced benthic invertebrate and fish assemblages in deeper bay areas affected by hypoxia caused by salinity stratification. Lower Perdido Bay was adversely affected by nonpoint source runoff from agricultural and urban sources with diminished water quality and loss of sediment organisms. Cumulative impacts due to anthropogenic nutrient loading from multiple sources and associated plankton blooms, along with altered physicochemical conditions due to a dredged opening at the bay terminus, resulted in widespread reductions of secondary productivity in Perdido Bay. Long‐term trends of bay productivity are the result of interactions of natural climatological cycles and anthropogenic activities.
ATMOSPHERIC NITROGEN DEPOSITION TO THE NEW JERSEY COASTAL WATERS AND ITS IMPLICATIONS
Authors: Gao Yuan , Kennish Michael J. , Flynn Amanda McGuirk
Published: July 2007

In situ measurements of atmospheric NO3− and NH4+ at Sandy Hook on the northern New Jersey (USA) coast and at Tuckerton on the southern New Jersey coast reveal significant temporal and spatial variations of these inorganic N constituents. The mean concentration of NO3− in precipitation was higher at Sandy Hook (44.6 μmol/L) than at Tuckerton (29.1 μmol/L). The mean concentration of NH4+ in precipitation exhibited a similar pattern, being higher at Sandy Hook (26.3 μmol/L) than at Tuckerton (18.3 μmol/L). Aerosol NO3− and NH4+ concentrations at Sandy Hook were also higher than those at Tuckerton. On an annual basis, the total atmospheric deposition of NO3− was estimated to be 51.1 mmol·m−2·yr−1 at Sandy Hook and 32.9 mmol·m−2·yr−1 at Tuckerton. For NH4+, the total atmospheric deposition was 32.8 mmol·m−2·yr−1 at Sandy Hook and 20.3 mmol·m−2·yr−1 at Tuckerton. Wet deposition accounted for up to 89% of the total NO3− deposition and 76–91% of the total NH4+ deposition on the New Jersey coast.

By comparison, NO3− and NH4+ concentrations are relatively low in estuarine waters of New Jersey. The annual mean NO3− concentrations recorded in surface waters of the Mullica River–Great Bay Estuary near the Tuckerton atmospheric site during the 2002–2004 period were as follows: 12.1 μmol/L for the upper estuary, 4.5 μmol/L for the mid‐estuary, 2.5 μmol/L for the lower estuary, and 1.2 μmol/L for the bay inlet area. The annual mean NH4+ concentrations in these waters were as follows: 1.5 μmol/L for the upper estuary, 3.8 μmol/L for the mid‐estuary, 3.8 μmol/L for the lower estuary, and 2.4 μmol/L for the bay inlet area. In the Barnegat Bay–Little Egg Harbor Estuary, the mean concentrations of NO3− plus NO2− were <4 μmol/L. In this system, atmospheric deposition accounts for ∼39% of the total N load. These results suggest that atmospheric deposition appears to be an important pathway of new N inputs to New Jersey coastal waters and a potentially significant N enrichment source for biotic production.
NLOAD: AN INTERACTIVE, WEB‐BASED MODELING TOOL FOR NITROGEN MANAGEMENT IN ESTUARIES
Authors: Bowen Jennifer L. , Ramstack Joy M. , Mazzilli S. , Valiela Ivan
Published: July 2007

Eutrophication of estuaries is an increasing global concern that requires development of new tools to identify causes, quantify conditions, and propose management options that address this environmental problem. Since eutrophication is often associated with increased inputs of land‐derived nitrogen to estuaries, we developed NLOAD, a user‐friendly, web‐based tool that brings together six different published models that predict nitrogen loading to estuaries and two models that estimate nitrogen concentrations in coastal waters. Here we describe each of the models, demonstrate how NLOAD is designed to function, and then use the models in NLOAD to predict nitrogen loads to Barnegat Bay, New Jersey (USA). The four models that we used to estimate nitrogen loads to Barnegat Bay, when adjusted, all had similar results that matched well with measured values and indicated that Barnegat Bay receives roughly 26 kg N·ha−1·yr−1. Atmospheric deposition was the dominant source of nitrogen to Barnegat Bay, followed by fertilizer nitrogen. Wastewater in Barnegat Bay is diverted to an offshore outfall and contributes no nitrogen to the system. The NLOAD tool has an additional feature that allows managers to assess the effectiveness of a variety of management options to reduce nitrogen loads. We demonstrate this feature of NLOAD through simulations in which fertilizer inputs to the Barnegat Bay watershed are reduced. Even modest cutbacks in the use of fertilizers on agricultural fields and lawns can be shown to reduce the amount of N entering Barnegat Bay.
LINKING WATER QUALITY TO LIVING RESOURCES IN A MID‐ATLANTIC LAGOON SYSTEM, USA
Authors: Wazniak Catherine E. , Hall Matthew R. , Carruthers Tim J. B. , Sturgis Brian , Dennison William C. , Orth Robert J.
Published: July 2007

The mid‐Atlantic coastal bays are shallow coastal lagoons, separated from the Atlantic Ocean by barrier sand islands with oceanic exchanges restricted to narrow inlets. The relatively poor flushing of these lagoon systems makes them susceptible to eutrophication resulting from anthropogenic nutrient loadings. An intensive water quality and seagrass monitoring program was initiated to track ecological changes in the Maryland and Virginia coastal bays. The purpose of this study was to analyze existing monitoring data to determine status and trends in eutrophication and to determine any associations between water quality and living resources. Analysis of monitoring program data revealed several trends: (1) decadal decreases in nutrient and chlorophyll concentrations, followed by recently increasing trends; (2) decadal increases in seagrass coverage, followed by a recent period of no change; (3) blooms of macroalgae and brown tide microalgae; and (4) exceedance of water quality thresholds: chlorophyll a (15 μg/L), total nitrogen (0.65 mg/L or 46 μmol/L), total phosphorus (0.037 mg/L or 1.2 μmol/L), and dissolved oxygen (5 mg/L) in many areas within the Maryland coastal bays. The water quality thresholds were based on habitat requirements for living resources (seagrass and fish) and used to calculate a water quality index, which was used to compare the bay segments. Strong gradients in water quality were correlated to changes in seagrass coverage between segments. These factors indicate that these coastal bays are in a state of transition, with a suite of metrics indicating degrading conditions. Continued monitoring and intensified management will be required to avert exacerbation of the observed eutrophication trends. Coastal lagoons worldwide are experiencing similar degrading trends due to increasing human pressures, and assessing status and trends relative to biologically relevant thresholds can assist in determining monitoring and management priorities and goals.
SEASONAL AND INTERANNUAL TRENDS IN NITROGEN AND BROWN TIDE IN MARYLAND'S COASTAL BAYS
Authors: Glibert Patricia M. , Wazniak Catherine E. , Hall Matthew R. , Sturgis Brian
Published: July 2007

A retrospective analysis revealed that water quality in the coastal bays of Maryland (USA) has been declining over the past decade, as evidenced by increases in total nitrogenous nutrients and in outbreaks of brown tides caused by the pelagophyteAureococcus anophagefferns. However, the increases in total nitrogen are not a function of increases in inorganic nitrogen, but rather a function of increases in dissolved organic nitrogen (DON). A near‐decadal record (1996–2004) demonstrates that an approximate doubling of DON over this time period correlates with a similar increase in total chlorophyll and an even larger increase in the proportion of chlorophyll that is composed of brown tide. Additionally, on an annual basis overall chlorophyll levels and strength of the brown‐tide blooms were related to the DON availability that developed during the prior months.Aureococcus anophagefferensis a harmful algal bloom species that preferentially uses DON for its nutrition over inorganic nitrogen forms and thus is a symptom of organic rather than inorganic nitrogen‐based eutrophication. These results demonstrate that long‐term changes in nutrient quantity and composition have occurred in the coastal bays of Maryland during the past decade and that total phytoplankton biomass, as well as the proliferation of brown tide, are related to these changes. Whether these changes are evidence of a long‐term trajectory or represent a short‐term anomaly will be revealed in future monitoring.
SEDIMENTS TELL THE HISTORY OF EUTROPHICATION AND HYPOXIA IN THE NORTHERN GULF OF MEXICO
Authors: Rabalais Nancy N. , Turner R. Eugene , Gupta Barun K. Sen , Platon Emil , Parsons Michael L.
Published: July 2007

We examined a suite of paleoindicators in 210Pb‐dated sediment cores to determine the historical course of primary production, eutrophication, and oxygen stress in the coastal ocean adjacent to the plumes of the Mississippi and Atchafalaya rivers. The assumption that hypoxia is a natural feature of the coastal ecosystem in the northern Gulf of Mexico influenced by the discharge of the Mississippi River system is not supported by paleoindicators in accumulated sediments. There is a propensity for the ecosystem to develop hypoxia because of the high discharge of the Mississippi River and physical dynamics on the continental shelf that support stratification. However, paleoindicators of eutrophication and oxygen conditions record recent anthropogenic influences. The evidence for increased carbon production and accumulation comes from diatoms and their remnants, marine‐origin carbon in the sediments, and phytoplankton pigments. Surrogates for oxygen condition, including mineral, isotopic, microfossil, and phytoplankton pigment indicators, indicate worsening oxygen stress. The changes are more apparent in areas of present chronic hypoxia and are coincident with the increasing nitrogen loads from the Mississippi River system beginning in the 1950s. Longer‐term shifts in offshore ecology parallel landscape changes within the watershed in the last two centuries. The temporal shifts in this coastal ecosystem parallel the time sequence of similarly eutrophied coastal waters globally and coincide nicely with sediment analyses from other locations.
Local IgE Production
Authors: Durham Stephen R. , Smurthwaite Lyn , Gould Hannah J.
Published: July 2007

Recent data from a number of groups have confirmed that IgE antibody may be produced, at least in part, locally within the nasal mucosa. Our data support the theory that B cell switching may also occur locally, although this remains to be confirmed. Local IgE may account for local disease expression in atopic subjects, although it is not clear which step is rate-limiting in this process. Our results highlight the importance of developing local strategies targeted against IgE for treatment of allergic diseases.
Diagnostic Evaluation of Mucociliary Transport: From Symptoms to Coordinated Ciliary Activity after Ciliogenesis in Culture
Authors: Jorissen Mark , Willems Tom , De Boeck Kris
Published: July 2007

Mucociliary transport is one of the most important local defense mechanisms of the airways, but it is prone to many and frequent acquired abnormalities and to inherited abnormalities. These abnormalities result in basic physiologic disturbances leading to a number of respiratory symptoms and signs. In order to critically evaluate the diagnostic value of parameters of this mucociliary cascade, the results of ciliary investigations in over 500 individuals (controls, acquired, and inherited abnormalities) were reviewed. Ciliary beat frequency, ciliary coordination and ultrastructural abnormalities were measured and evaluated in biopsies and after ciliogenesis in culture. There is a considerable overlap for all investigated parameters in biopsy material of controls, secondary, and primary ciliary dyskinesia. There is not one parameter that is diagnostic for primary ciliary dyskinesia or can be used as an exclusion criterion. After ciliogenesis in culture, cilia are always completely normal except for the inherited abnormalities. Absence of coordinated ciliary activity after ciliogenesis in culture is 100% sensitive and specific for the diagnosis of primary ciliary dyskinesia.
Pathophysiology of Nasal Symptoms
Authors: Eccles Ronald
Published: July 2007

Symptoms are perceived by the patient and all nasal symptoms must eventually relate to stimulation of sensory nerves or some change in the activity of the CNS. Although it is the symptoms that are of prime importance to the patient, the role of sensory nerves and psychology in the generation and perception of symptoms has been relatively neglected compared to the large amount of research on inflammatory mediators. This paper discusses how physical and chemical changes in the nasal epithelium result in the generation of inflammatory mediators that are responsible for symptoms. Inflammatory mediators can cause symptoms in three ways. (J) By having direct action on glands and blood vessels to cause glandular secretion, vasodilation, increased vascular permeability, and transudation of a plasma exudate. (2) By stimulation of sensory nerve endings to cause reflex glandular secretion, sneezing, and sensations such as itching, irritation, pain, and pressure. (3) By effects on the central nervous system to cause, headache, fever, tiredness, and mood changes.
Local IgE Production in the Nasal Mucosa: A Review
Authors: Fokkens Wytske J. , Vinke Jeroen G. , KleinJan Alex
Published: July 2007

IgE is one of the most important markers for allergy. The presence of specific IgE on skin mast cells (skin test) and/or the existence of specific IgE in serum (RAST) indicates sensitization, but not necessarily clinical allergy, in the target organ. Discrepancies between sensitization and disease could be explained by local IgE production. The nasal mucosa contains all the cell types necessary for a local IgE immune response. Moreover, it has been shown that this local IgE is specific for the specific allergen to which the patient is allergic. The availability of IL-4 and IL-13 produced in the nasal mucosa creates the possibility for isotype switching of B cells to IgE-positive B cells, and proliferation and maturation of B cells to IgE-producing plasma cells. The IgE positivity of B cells and plasma cells implies that IgE production occurs in the nasal mucosa. The observation of the presence of allergen-positive plasma cells and the finding that all allergen-positive cells were also IgE-positive indicates that this local IgE production is allergen-specific. Data discussed in this review provide strong evidence for the local production of specific IgE in the nasal mucosa.