The benefits of contributing to the citizen science platform iNaturalist as an identifier

As the number of observations submitted to the citizen science platform iNaturalist continues to grow, it is increasingly important that these observations can be identified to the finest taxonomic level, maximizing their value for biodiversity research. Here, we explore the benefits of acting as an identifier on iNaturalist.

Lifting the lid on GPCRs: the role of extracellular loops

GPCRs exhibit a common architecture of seven transmembrane helices (TMs) linked by intracellular loops and extracellular loops (ECLs). Given their peripheral location to the site of G-protein interaction, it might be assumed that ECL segments merely link the important TMs within the helical bundle of the receptor. However, compelling evidence has emerged in recent years revealing a critical role for ECLs in many fundamental aspects of GPCR function, which supported by recent GPCR crystal structures has provided mechanistic insights. This review will present current understanding of the key roles of ECLs in ligand binding, activation and regulation of both family A and family B GPCRs.

The rotating wall machine: a device to study ideal and resistive magnetohydrodynamic stability under variable boundary conditions

The rotating wall machine, a basic plasma physics experimental facility, has been constructed to study the role of electromagnetic boundary conditions on current-driven ideal and resistive magnetohydrodynamic instabilities, including differentially rotating conducting walls. The device, a screw pinch magnetic geometry with line-tied ends, is described. The plasma is generated by an array of 19 plasma guns that not only produce high density plasmas but can also be independently biased to allow spatial and temporal control of the current profile. The design and mechanical performance of the rotating wall as well as diagnostic capabilities and internal probes are discussed. Measurements from typical quiescent discharges show the plasma to be high β (≤p>2μ(0)/B(z)(2)), flowing, and well collimated. Internal probe measurements show that the plasma current profile can be controlled by the plasma gun array.

Extracellular loops and ligand binding to a subfamily of Family A G-protein-coupled receptors

GPCRs (G-protein-coupled receptors) are a large family of structurally related proteins which mediate their effects by coupling to G-proteins. The V(1a)R (V(1a) vasopressin receptor) is a member of a family of related GPCRs that are activated by vasopressin {AVP ([Arg(8)]vasopressin)}, OT (oxytocin) and related peptides. These receptors are members of a subfamily of Family A GPCRs called the neurohypophysial peptide hormone receptor family. GPCRs exhibit a conserved tertiary structure comprising a bundle of seven TM (transmembrane) helices linked by alternating ECLs (extracellular loops) and ICLs (intracellular loops). The cluster of TM helices is functionally important for ligand binding, and, furthermore, activation of GPCRs involves movement of these TM helices. Consequently, it might be assumed that the extracellular face of GPCRs is composed of peptide linkers that merely connect important TM helices. However, using a systematic mutagenesis approach and focusing on the N-terminus and the second ECL of the V(1a)R, we have established that these extracellular domains fulfil a range of important roles with respect to GPCR signalling, including agonist binding, ligand selectivity and receptor activation.

Onset and saturation of the kink instability in a current-carrying line-tied plasma

An internal kink instability is observed to grow and saturate in a line-tied screw pinch plasma. Detailed measurements show that an ideal, line-tied kink mode begins growing when the safety factor q = (4pi2r2B(z))/(mu0I(p)(r)L) drops below 1 inside the plasma; the saturated state corresponds to a rotating helical equilibrium. In addition to the ideal mode, reconnection events are observed to periodically flatten the current profile and change the magnetic topology.

Gradual painless visual loss: glaucoma

Glaucoma is one of the leading causes of blindness in adult Americans. This disease remains undetected in one half of the people with this disease. Primary open angle glaucoma is the most common form of the disease. Patients at risk for glaucoma usually have one or more of the following characteristics: advanced age, diabetes, myopia, elevated intraocular pressure, large cup to disc ratio, and a positive family history of the disease. Presently in the United States, treatment for primary open angle glaucoma is usually medical. Six classes of glaucoma medications are available, all of which have side effects. The second most prevalent form of glaucoma is angle closure glaucoma, the treatment for which is usually surgical. Although a cure for the various forms of glaucoma does not exist, an awareness of the problem and early detection and treatment minimize the impact of the disease.

The results of ab interno laser thermal sclerostomy combined with cataract surgery versus trabeculectomy combined with cataract surgery 6 to 12 months postoperatively

BACKGROUND AND OBJECTIVE

When cataract surgery and glaucoma surgery are combined, the theoretical advantages of pressure control, removal of the visual impairment, and protection against an increase in intraocular pressure (IOP) in the immediate postoperative period are gained. The authors' objective was to determine whether ab interno laser thermal sclerostomy (LTS) combined with cataract surgery would be as effective as trabeculectomy combined with cataract surgery.

PATIENTS AND METHODS

Ab interno LTS was compared with trabeculectomy, retrospectively, for patients who had undergone combined cataract and glaucoma surgery.

RESULTS

There was no significant difference in the numbers of patients using no medications or fewer medications at 6 and 12 months. There was a greater reduction in IOP in the LTS group.

CONCLUSIONS

LTS may be better than trabeculectomy in combined cataract and glaucoma surgery because it reduces the IOP more. Compared with trabeculectomy, LTS is simpler to perform and adds less operating time to cataract surgery. Continued follow-up is recommended.

Intravenous diclofenac sodium. Does its administration before operation suppress postoperative pain?

Intravenous diclofenac sodium was evaluated in a double-blind randomised trial relative to intramuscular diclofenac, intravenous fentanyl, and intramuscular placebo in 160 patients undergoing extraction of impacted lower third molar teeth. The test drug was administered before operation in an attempt to alleviate postoperative pain. A 10-cm visual analogue scale was used to assess pain at 30 minutes and one day after surgery, if the patients stayed overnight. Patients who received intravenous diclofenac had significantly less pain than the other groups 30 minutes after operation. They also had significantly less pain one day after surgery than the placebo or opioid groups, but not less than the intramuscular diclofenac group. Capillary bleeding time, in comparison with placebo, was significantly prolonged after the use of intramuscular diclofenac, and a similar but nonsignificant trend was observed in the intravenous diclofenac group. No problems were encountered with excessive bleeding in any group.

Pharmacists and their relationship with elderly patients

A survey of 60 randomly selected pharmacists explored their relationship with elderly patients, including their information storage systems, dispensing practices and the major problems they encounter with these patients. Nearly all the pharmacists kept a medication profile for each elderly patient, and one third used a computer, which facilitated recording of additional information. However, few recorded the age of the patient. Many pharmacists counselled their elderly patients on the correct use of medications, but few provided counselling on the use of nonprescription drugs. Most of the pharmacists reported using techniques to improve compliance among elderly patients. More than 80% of the pharmacists reported apparently inappropriate prescribing by physicians at least occasionally.

Compliance with prescribed medication by elderly patients

Factors contributing to improper use of medication were examined in 40 patients aged 65 years or more who were in a home care program. They reported taking an average of 3.8 prescription medications and 1.2 nonprescription medications each. Pill counts showed that they were actually taking 57% of the prescribed medications; compliance decreased with the number of medications concurrently prescribed. Poor labelling instructions, difficulty opening childproof containers and misunderstanding of verbal instructions contributed to this problem. The patients tended to rely more on physicians than on pharmacists or visiting nurses for advice problems with medication.