Rethinking Aerobic Respiration in the Hyporheic Zone under Variation in Carbon and Nitrogen Stoichiometry.

Hyporheic zones (HZs)─zones of groundwater-surface water mixing─are hotspots for dissolved organic matter (DOM) and nutrient cycling that can disproportionately impact aquatic ecosystem functions. However, the mechanisms affecting DOM metabolism through space and time in HZs remain poorly understood. To resolve this gap, we investigate a recently proposed theory describing trade-offs between carbon (C) and nitrogen (N) limitations as a key regulator of HZ metabolism. We propose that throughout the extent of the HZ, a single process like aerobic respiration (AR) can be limited by both DOM thermodynamics and N content due to highly variable C/N ratios over short distances (centimeter scale). To investigate this theory, we used a large flume, continuous optode measurements of dissolved oxygen (DO), and spatially and temporally resolved molecular analysis of DOM. Carbon and N limitations were inferred from changes in the elemental stoichiometric ratio. We show sequential, depth-stratified relationships of DO with DOM thermodynamics and organic N that change across centimeter scales. In the shallow HZ with low C/N, DO was associated with the thermodynamics of DOM, while deeper in the HZ with higher C/N, DO was associated with inferred biochemical reactions involving organic N. Collectively, our results suggest that there are multiple competing processes that limit AR in the HZ. Resolving this spatiotemporal variation could improve predictions from mechanistic models, either via more highly resolved grid cells or by representing AR colimitation by DOM thermodynamics and organic N.

Metabolic multireactor: Practical considerations for using simple oxygen sensing optodes for high-throughput batch reactor metabolism experiments.

We present a system for carrying out small batch reactor oxygen consumption experiments on water and sediment samples for environmental questions. In general, it provides several advantages that can help researchers achieve impactful experiments at relatively low costs and high data quality. In particular, it allows for multiple reactors to be operated and their oxygen concentrations to be measured simultaneously, providing high throughput and high time-resolution data, which can be advantageous. Most existing literature on similar small batch-reactor metabolic studies is limited to either only a few samples, or only a few time points per sample, which can restrict the ability for researchers to learn from their experiments. The oxygen sensing system is based very directly on the work of Larsen, et al. [2011], and similar oxygen sensing technology is widely used in the literature. As such we do not delve deeply into the specifics of the fluorescent dye sensing mechanism. Instead, we focus on practical considerations. We describe the construction and operation of the calibration and experimental systems, and answer many of the questions likely to come up when other researchers choose to build and operate a similar system themselves (questions we ourselves had when we first built the system). In this way, we hope to provide an approachable and easy to use research article that can help other researchers construct and operate a similar system that can be tailored to ask their own research questions, with a minimum of confusion and missteps along the way.

Laboratory evaluation of open source and commercial electrical conductivity sensor precision and accuracy: How do they compare?

Variation in the electrical conductivity (EC) of water can reveal environmental disturbance and natural dynamics, including factors such as anthropogenic salinization. Broader application of open source (OS) EC sensors could provide an inexpensive method to measure water quality. While studies show that other water quality parameters can be robustly measured with sensors, a similar effort is needed to evaluate the performance of OS EC sensors. To address this need, we evaluated the accuracy (mean error, %) and precision (sample standard deviation) of OS EC sensors in the laboratory via comparison to EC calibration standards using three different OS and OS/commercial-hybrid (OS/C) EC sensors and data logger configurations and two commercial (C) EC sensors and data logger configurations. We also evaluated the effect of cable length (7.5 m and 30 m) and sensor calibration on OS sensor accuracy and precision. We found a significant difference between OS sensor mean accuracy (3.08%) and all other sensors combined (9.23%). Our study also found that EC sensor precision decreased across all sensor configurations with increasing calibration standard EC. There was also a significant difference between OS sensor mean precision (2.85 µS/cm) and the mean precision of all other sensors combined (9.12 µS/cm). Cable length did not affect OS sensor precision. Furthermore, our results suggest that future research should include evaluating how performance is impacted by combining OS sensors with commercial data loggers as this study found significantly decreased performance in OS/commercial-hybrid sensor configurations. To increase confidence in the reliability of OS sensor data, more studies such as ours are needed to further quantify OS sensor performance in terms of accuracy and precision across different settings and OS sensor and data collection platform configurations.

High-resolution magnetic resonance histology of the embryonic and neonatal mouse: a 4D atlas and morphologic database.

Engineered mice play an ever-increasing role in defining connections between genotype and phenotypic expression. The potential of magnetic resonance microscopy (MRM) for morphologic phenotyping in the mouse has previously been demonstrated; however, applications have been limited by long scan times, availability of the technology, and a foundation of normative data. This article describes an integrated environment for high-resolution study of normal, transgenic, and mutant mouse models at embryonic and neonatal stages. Three-dimensional images are shown at an isotropic resolution of 19.5 microm (voxel volumes of 8 pL), acquired in 3 h at embryonic days 10.5-19.5 (10 stages) and postnatal days 0-32 (6 stages). A web-accessible atlas encompassing this data was developed, and for critical stages of embryonic development (prenatal days 14.5-18.5), >200 anatomical structures have been identified and labeled. Also, matching optical histology and analysis tools are provided to compare multiple specimens at multiple developmental stages. The utility of the approach is demonstrated in characterizing cardiac septal defects in conditional mutant embryos lacking the Smoothened receptor gene. Finally, a collaborative paradigm is presented that allows sharing of data across the scientific community. This work makes magnetic resonance microscopy of the mouse embryo and neonate broadly available with carefully annotated normative data and an extensive environment for collaborations.

Modeling the airborne survival of influenza virus in a residential setting: the impacts of home humidification.

BACKGROUND: Laboratory research studies indicate that aerosolized influenza viruses survive for longer periods at low relative humidity (RH) conditions. Further analysis has shown that absolute humidity (AH) may be an improved predictor of virus survival in the environment. Maintaining airborne moisture levels that reduce survival of the virus in the air and on surfaces could be another tool for managing public health risks of influenza. METHODS: A multi-zone indoor air quality model was used to evaluate the ability of portable humidifiers to control moisture content of the air and the potential related benefit of decreasing survival of influenza viruses in single-family residences. We modeled indoor AH and influenza virus concentrations during winter months (Northeast US) using the CONTAM multi-zone indoor air quality model. A two-story residential template was used under two different ventilation conditions - forced hot air and radiant heating. Humidity was evaluated on a room-specific and whole house basis. Estimates of emission rates for influenza virus were particle-size specific and derived from published studies and included emissions during both tidal breathing and coughing events. The survival of the influenza virus was determined based on the established relationship between AH and virus survival. RESULTS: The presence of a portable humidifier with an output of 0.16 kg water per hour in the bedroom resulted in an increase in median sleeping hours AH/RH levels of 11 to 19% compared to periods without a humidifier present. The associated percent decrease in influenza virus survival was 17.5 - 31.6%. Distribution of water vapor through a residence was estimated to yield 3 to 12% increases in AH/RH and 7.8-13.9% reductions in influenza virus survival. CONCLUSION: This modeling analysis demonstrates the potential benefit of portable residential humidifiers in reducing the survival of aerosolized influenza virus by controlling humidity indoors.

Daniel John Cunningham (1850-1909): anatomist and textbook author, whose sons achieved distinction in the Army, Navy and Indian Medical Service.

Daniel John Cunningham was a son of the manse. His father John (1819-93) was the parish priest at Crieff, Perthshire from 1845 and was to remain there for 41 years. In 1886 he was appointed Principal of St Mary's College of the University of St Andrews and Moderator of the Church of Scotland. Daniel was educated at Crieff Academy before he progressed to the University of Edinburgh. He graduated MB CM with First-class Honours in 1874 and then proceeded MD in 1876 when he was awarded a Gold Medal for his thesis. He acted as Demonstrator to Professor Turner (1832-1916) in Edinburgh for eight years until 1882 and was then appointed to the Chair of Anatomy at the Royal College of Surgeons of Ireland, in Dublin. After only one year there, he transferred to Trinity College, Dublin, where he occupied a similar position for 20 years. In 1903, on the appointment of Sir William Turner to the post of Principal and Vice-Chancellor of the University of Edinburgh, Daniel was invited to succeed him as Professor of Anatomy in Edinburgh. Daniel held this post until his premature death in 1909. He had three sons and two daughters. Each of his three sons achieved distinction in different fields - one in the Army, another in the Navy and the third in the Indian Medical Service. One of Daniel's daughters married Dr Edwin Bramwell (1873-1952), who was later to occupy the Moncrieff Arnott Chair of Clinical Medicine in the University of Edinburgh.

William Gregory (1803-58): Professor of Chemistry at the University of Edinburgh and enthusiast for phrenology and mesmerism.

William Gregory was descended from a long line of academics. Although he graduated in medicine, he had earlier determined on a career in Chemistry but more particularly to succeed Professor Thomas Charles Hope in the Edinburgh Chair in that discipline. At various times during the 1830s and 1840s he studied Chemistry at Giessen in Germany under Professor Justus Liebig and was closely associated with him over the succeeding years, translating and editing in all seven of his books. Gregory taught initially in London, at the Edinburgh Extra-mural School, in Dublin, at the Andersonian University, Glasgow and as Mediciner and Professor of Chemistry in Aberdeen. In 1844 he was appointed to the Chair of Chemistry in Edinburgh and remained in this post until his death in 1858. Shortly after he graduated he joined the Edinburgh Phrenological Society (he was initially its Secretary and later President) and took a particularly active role in the meetings of this Society and in the Aberdeen Phrenological Society. He was also interested in the phenomena of Mesmerism and Mesmero-Phrenology, despite the agitation and scorn of many of his academic colleagues both in Aberdeen and in Edinburgh.

Parthenogenetic Activation of Oocytes.

Numerous studies have been initiated to investigate the influence of maternal and paternal genomes on early mammalian development. For this type of study, parthenogenetic embryos provide a unique source of preimplantation and early postimplantation embryos that (by definition) develop in the absence of any contribution from a male gamete. Parthenogenetic activation is used for biochemical and morphological studies of oocytes during fertilization and early development and is a critical component of the cloning procedure. This protocol describes the activation of oocytes using ethanol. Parthenogenesis can also be induced by exposure of unfertilized oocytes to strontium-containing medium.

Sir Charles Bell (1774-1842): contributions to neuro-ophthalmology.

Sir Charles Bell (1774-1842) was a Scottish anatomist, physiologist, neurologist, artist and surgeon, who enjoyed a distinguished career in teaching and clinical practice in London between 1804 and 1836. In 1814, he was appointed to the surgical staff of the Middlesex Hospital. In 1824, he was elected Professor of Anatomy and Surgery at the Royal College of Surgeons of England, and shortly afterwards was elected Professor of Physiology at the University of London. In 1831, he was knighted on the accession of William IV. In 1836, he was elected to the Chair of Surgery in the University of Edinburgh, and remained there until his death in 1842, at 68 years of age. During his career, Bell was a prolific medical author, a brilliant medical researcher and a skilled artist. In 1811, he discovered the distinct functions of the motor and sensory nerves, findings that were initially published in a pamphlet entitled 'Ideas of a New Anatomy of the Brain'. In 1821, Bell described the long thoracic nerve, which supplies the serratus anterior muscle, and which now bears his name. In the same paper he showed that lesions of the seventh cranial nerve produce facial paralysis (now termed Bell's palsy). He also demonstrated that the fifth cranial nerve is of sensory importance to the face and controls the muscles of mastication, whereas the seventh cranial nerve principally controls the muscles of facial expression. Bell published research on a number of ophthalmological subjects. This paper reviews some of these latter achievements.

Sir George Ballingall (1786-1855): Regius Professor of Military Surgery in the University of Edinburgh.

George Ballingall qualified with the Licentiate Diploma of the Royal College of Surgeons of Edinburgh in December 1805 and joined the Army Medical Department in May of the following year, spending the majority of his army career in India. He also served in Java. Eventually, he was awarded his MD Edinburgh degree in 1819, and the FRCS Edinburgh and Fellowship of the Royal Society of Edinburgh during the following year. He was appointed to the Regius Chair of Military Surgery in the University of Edinburgh in November 1822, succeeding John Thomson, its first holder, and he held this post until his death in December 1855. Ballingall was the first to describe 'Madura Foot', sometimes called 'Ballingall's disease.' In 1833, he published Outlines of Military Surgery, which ran to five editions. He was appointed Surgeon-Extraordinary to the King (William IV) and Surgeon to the Queen. He also established a fine Museum Collection to complement his Lecture Course. Throughout his teaching career, he campaigned vigorously in support of military medical educational reform. One of his sons and several grandchildren also served in the medical service of the army or in that of the Honourable East India Company.

Classification of proliferative pulmonary lesions of the mouse: recommendations of the mouse models of human cancers consortium.

Rapid advances in generating new mouse genetic models for lung neoplasia provide a continuous challenge for pathologists and investigators. Frequently, phenotypes of new models either have no precedents or are arbitrarily attributed according to incongruent human and mouse classifications. Thus, comparative characterization and validation of novel models can be difficult. To address these issues, a series of discussions was initiated by a panel of human, veterinary, and experimental pathologists during the Mouse Models of Human Cancers Consortium (NIH/National Cancer Institute) workshop on mouse models of lung cancer held in Boston on June 20-22, 2001. The panel performed a comparative evaluation of 78 cases of mouse and human lung proliferative lesions, and recommended development of a new practical classification scheme that would (a) allow easier comparison between human and mouse lung neoplasms, (b) accommodate newly emerging mouse neoplasms, and (c) address the interpretation of benign and preinvasive lesions of the mouse lung. Subsequent discussions with additional experts in pulmonary pathology resulted in the current proposal of a new classification. It is anticipated that this classification, as well as the complementary digital atlas of virtual histological slides, will help investigators and pathologists in their characterization of new mouse models, as well as stimulate further research aimed at a better understanding of proliferative lesions of the lung.

Dr David Maclagan (1785-1865): distinguished Military Surgeon, President of both the Royal College of Surgeons and Royal College Physicians of Edinburgh, founder of a medical and military dynasty.

Dr David Maclagan studied medicine in Edinburgh, obtaining the LRCS Edin Diploma in 1804 and graduating with the MD degree in 1805. Because he was too young to enter the army, he spent a year in London, principally at St. George's Hospital, and he gained the MRCS England Diploma in 1807. Then he entered the army as an Assistant Surgeon associated with the 91st Foot Regiment. He served at Walcheren in 1809 and in the Peninsula. Later he was seconded as a Surgeon-Major to the 9th Portuguese Brigade. After his promotion to Physician to the Forces, he superintended the hospital arrangements of the Portuguese Army. Between 1811 and 1814 he sent a series of letters, principally to his wife, giving his personal impressions of his life in the war zone. He also maintained two personal diaries that nominally detailed his activities in the Peninsula between 1812 and 1813. After the end of the fighting he was put on half-pay and returned to Edinburgh. Then he gained the Fellowship of the Royal College of Surgeons of Edinburgh in 1816 and was appointed a Surgeon to the New Town Dispensary. After he established himself in private practice in Edinburgh he became the Honorary Consulting Surgeon to the Dispensary until shortly before his death. He was elected President of the Edinburgh College of Surgeons in 1826-27. He became a Fellow of the Royal College of Physicians of Edinburgh in 1848, and was elected its President in 1856-57. He founded an important medical and military dynasty. Three of his sons joined the medical profession and four served in the army. One of his sons was appointed Archbishop of York. His eldest son followed in his father's footsteps and was also President of both Royal Colleges, of Surgeons and Physicians, in Edinburgh. His widow, Jane, and his seven sons survived him.

Corneal abnormalities in Pax6+/- small eye mice mimic human aniridia-related keratopathy.

PURPOSE: To investigate corneal abnormalities in heterozygous Pax6(+/Sey-Neu) (Pax6(+/-), small eye) mice and compare them with aniridia-related keratopathy in PAX6(+/-) patients. METHODS: Fetal and postnatal corneal histopathology, adult corneal thickness, and the distribution of K12-immunostained cells were compared in wild-type and Pax6(+/-) mice. RESULTS: Prenatally, the corneal epithelium was thinner in Pax6(+/-) fetuses than wild-type littermates, but the stroma appeared irregular, hypercellular, and thickened. The anterior chamber angle was obliterated, and the iris was hypoplastic from early developmental stages. The adult Pax6(+/-) corneal epithelium was thinner, had fewer layers, and included goblet cells, indicating repopulation from conjunctival epithelium. The ocular surface was often roughened, with epithelial vacuolation and lens tissue within the stroma. The corneal stroma was thicker centrally, with an irregular lamellar alignment. Many adult Pax6(+/-) corneas were vascularized or contained cellular infiltrates, but some remained clear. Corneal degeneration was age-related: Older Pax6(+/-) mice had prominent subepithelial pannus and more goblet cells in the peripheral corneal epithelium. Cytokeratin 12 stained very weakly in the peripheral and superficial corneal epithelium in 12-month-old Pax6(+/-) mice. CONCLUSIONS: Corneal abnormalities in Pax6(+/-) mice are similar to those in aniridia-related keratopathy in PAX6(+/-) patients. This extends the relevance of this mouse model of human aniridia to include corneal abnormalities. Incursion of goblet cells suggests impaired function of Pax6(+/-) limbal stem cells, abnormal expression of cytokeratin 12 may result in greater epithelial fragility, and corneal opacities in older mice may reflect poor wound-healing responses to accumulated environmental insults.

Harry Goodsir and the last Franklin Expedition, of 1845.

Henry Duncan Spens ("Harry") Goodsir was one of the younger brothers of John Goodsir, Professor of Anatomy at the University of Edinburgh from 1846 to 1867. Harry Goodsir qualified with the LRCS Edinburgh diploma in 1840, and was an anatomist and naturalist of the highest promise. He was Conservator of the Museum of the Royal College of Surgeons of Edinburgh from 1843 until 1845, when he was appointed assistant surgeon and naturalist to the Franklin Expedition. This sailed to the Arctic seas under Sir John Franklin, to find the North-West Passage, but was lost. Its fate was never determined satisfactorily, although several subsequent expeditions attempted to do so.

Sir William Newbigging (1772-1852) and Patrick Newbigging (1813-1864)-father and son presidents of the Royal College of Surgeons of Edinburgh.

Sir William Newbigging was a surgeon to the Edinburgh Royal Infirmary from 1802. While a dextrous operator, he was regarded principally as an excellent general practitioner. He was President of the Royal College of Surgeons of Edinburgh 1814-16 and was knighted by Queen Victoria in 1838. He had five sons, four of whom followed him into the medical profession. Four of his sons died young-only Patrick outlived him. When Patrick returned from a Continental tour in 1842 he joined his father's general practice and when Sir William died in 1852 he took it over. From 1861 to 1863 he was also President of the Royal College of Surgeons of Edinburgh. His last few years were plagued by ill health and he died in 1864, shortly after his fiftieth birthday.

John Aitken (d. 1790)--grinder or scholar?

John Aitken attended the University of Edinburgh between 1763 and 1769 but did not graduate MD. He gained the membership (i.e. fellowship) of the Royal College of Surgeons of Edinburgh in 1770, and was for two sessions Senior President of the Royal Medical Society. Between 1771 and 1790 he published numerous books and pamphlets on surgery, medicine, midwifery, anatomy and physiology. As a surgeon at the Royal Infirmary, from 1779, he lectured on most subjects in the medical curriculum. John Struthers was particularly scathing of Aitken's scholarship, and this article attempts to restore Aitken's reputation as a scholar and probably one of the first of the extra-academical lecturers, who taught both anatomy and surgery in Edinburgh from 1779 until his death in 1790.

Hip disarticulation--the evolution of a surgical technique.

Introduced in the 18th century, hip disarticulation was considered to be one of the most radical operations performed for trauma or disease of the lower limb. The high morbidity and mortality associated with it ensured that it was a rarely performed procedure. It is fortunate that it remains extremely uncommon to the present day. Since the first successful hip disarticulation was described, a number of important advances have occurred. General medical care has improved dramatically and the development of anaesthesia, analgesics, antibiotics and blood transfusions has resulted in greatly decreased morbidity associated with this dramatic operation. This review on the history of hip disarticulation outlines the surgical evolution of the operation, the indications for its use and the techniques used. It draws on the early experiences and preferred techniques of the surgeons of the 19th century, with some discussion on the methods employed to reduce intraoperative haemorrhage. Further development of techniques in the 20th century is also described together with discussion on the evolution of hindquarter amputation.

Genetic influences on ovulation of primary oocytes in LT/Sv strain mice.

A high proportion of LT/Sv strain oocytes arrest in meiotic metaphase I (MI) and are ovulated as diploid primary oocytes rather than haploid secondary oocytes. (Mus musculus castaneus x LT/SvKau)F1 x LT/SvKau backcross females were analysed for the proportion of oocytes that arrested in MI and typed by PCR for a panel of microsatellite DNA sequences (simple sequence repeat polymorphisms) that differed between strain LT/SvKau and M. m. castaneus. This provided a whole genome scan of 86 genetic markers distributed over all 19 autosomes and the X chromosome, and revealed genetic linkage of the MI arrest phenotype to markers on chromosomes 1 and 9. Identification of these two chromosomal regions should facilitate the identification of genes involved in mammalian oocyte maturation and the control of meiosis.