Crop production in the USA is frequently limited by a lack of pollinators

Most of the world's crops depend on pollinators, so declines in both managed and wild bees raise concerns about food security. However, the degree to which insect pollination is actually limiting current crop production is poorly understood, as is the role of wild species (as opposed to managed honeybees) in pollinating crops, particularly in intensive production areas. We established a nationwide study to assess the extent of pollinator limitation in seven crops at 131 locations situated across major crop-producing areas of the USA. We found that five out of seven crops showed evidence of pollinator limitation. Wild bees and honeybees provided comparable amounts of pollination for most crops, even in agriculturally intensive regions. We estimated the nationwide annual production value of wild pollinators to the seven crops we studied at over $1.5 billion; the value of wild bee pollination of all pollinator-dependent crops would be much greater. Our findings show that pollinator declines could translate directly into decreased yields or production for most of the crops studied, and that wild species contribute substantially to pollination of most study crops in major crop-producing regions.

Diagnosing the cause of bilateral paediatric cataracts: comparison of standard testing with a next-generation sequencing approach

PurposeIn addition to environmental causes such as TORCH infection, trauma and drug or chemical exposure, childhood cataracts (CC) frequently have a genetic basis. They may be isolated or syndromic and have been associated with mutations in over 110 genes. We have recently demonstrated that next-generation sequencing (NGS), a high throughput sequencing technique that enables the parallel sequencing of multiple genes, is ideally suited to the investigation of bilateral CC. This study assesses the diagnostic outcomes of traditional routine investigations and compares this with outcomes of NGS testing.MethodsA retrospective review of the medical records of 27 consecutive patients with bilateral CC presenting in 2010-2012 was undertaken. The outcomes of routine investigations in these patients, including TORCH screen, urinalysis, karyotyping, and urinary and plasma organic amino acids, were collated. The success of routine genetic investigations undertaken over 10 years (2000-2010) was also assessed.ResultsBy April 2014, the underlying cause of bilateral CC had been identified in just one of 27 patients despite 44% (n=12) receiving a full 'standard' investigative work-up and 22% (n=6) investigations in addition to the standard work-up. Fifteen of these patients underwent NGS testing and nine (60%) of these received a diagnosis for their CC.ConclusionThe frequency of patients receiving a diagnosis for their CC after standard care and the time taken to diagnosis was disappointing. NGS testing improved diagnostic rates and time to diagnosis, as well as changing clinical management. These data serve as a baseline for future evaluation of novel diagnostic modalities.

Post-ratoon growth and yield of three hybrid papayas (Carica papaya L.) under mulched and bare-ground conditions

At Yarwun (151.3°E, 23.75°S), a trial was conducted to compare 3 papaya hybrids (Hybrid 29, Hybrid 11 and Hybrid 13) under mulching with grass hay or in bare ground. The viability of ratooning a papaya crop was also investigated. After a 16-month cropping season plants were cut to a 750-mm stump (ratooned) about monthly over a 3.5-month period and, following a 4.5-month regrowth period, were harvested for a period of 11 months (post-ratoon). Hybrid 29 yielded (by weight) 54% more than Hybrid 11 and 92% more than Hybrid 13 during the 3.5-month ratooning period. At the commencement of ratooning, Hybrid 29 plants were 41–58 cm shorter than Hybrid 11 and 13 plants, allowing the Hybrid 29 plants to be retained for longer before being ratooned. Hybrid 29 also returned to fruiting more quickly with a greater proportion of plants (97%) with fruit at the first post-ratoon harvest compared with Hybrid 11 (87%). Following regrowth (post-ratoon) the 3 hybrids produced similar yields. All 3 hybrids were equally susceptible to the 3 phytoplasma diseases and to nematodes. The plots mulched with coarse grass hay yielded 70% more during the ratooning period and 116% more post-ratoon than the plots with bare ground. This difference was attributed in part to fewer root-knot nematodes, the roots being more heavily infected with vesicular arbuscular mycorrhiza, the use of the complete upper soil profile by the roots, reduced rainfall run off and less soil loss in the mulched treatment. The highest yielding treatment, mulched Hybrid 29, averaged the equivalent of 55 t/ha.year during ratooning, 43 t/ha.year over the 11-month post-ratoon harvest period and 65 t/ha.year over the entire plant–ratoon cycle. These yields were achieved in spite of drought conditions and quite severe outbreaks of the phytoplasma diseases, dieback, yellow crinkle and mosaic, with 60% of plant positions infected with dieback during the post-ratoon period. Theoretical yield estimations using the data from the plant and post-ratoon crops indicated that ratooning may give superior average monthly yields compared with 2 successive plant crops because of the reduced time required for the ratooned crop to return to production. The study demonstrated the benefits of mulching, the superiority of Hybrid 29 and that ratooning may be successfully used in papaya. In environments similar to Yarwun, Hybrid 29, or similar hybrids, with mulching is recommended for commercial production. If land, time or finances are limiting, consideration should be given to ratooning the plant crop based on monthly cut outs over a 3–4-month ratooning period with vacant plant positions replanted during ratooning.

Growth, yield and phenology of 2 hybrid papayas (Carica papaya L.) as influenced by method of water application

Highly variable, outcrossed papaya lines irrigated with overhead sprinklers were grown at Yarwun (151.3˚E, 23.75˚S) in Queensland, Australia. The inherent variability made scientifically based comparative studies impractical. The advent of uniform hybrid papaya lines allowed the testing of 2 of these hybrids under 3 irrigation methods, 2 of which had the potential to greatly reduce water use compared with overhead sprinklers. Yields of 92 t/ha.year were achieved by both papaya Hybrids 29 and 1E. Water application method did not influence yield. About 26% of plants were lost due to the phytoplasma diseases dieback, yellow crinkle and mosaic over the life of the trial. Downward yield fluctuations were related to poor fruit set in winter when pollinators (Family Sphingidae) were not present and growth was slow due to hot dry periods affecting fruit set. The resultant fruit (about 6 months later) were small and reduced in number. Irrigation with overhead sprinklers using saline water (1400–4000 S/cm) damaged leaves and reduced growth of plants. Winter spot was most severe in July, August and September, in Hybrid 29 with overhead irrigation. Height of plants 13 weeks after planting was greater under trickle irrigation due to less damage from the saline water supply than in the overhead sprinkler treatment. Hybrid 29 set fruit at 94.3 cm above ground compared with 117.6 cm for Hybrid 1E.

Arterial microembolisation: an unusual presentation of dilated cardiomyopathy

Systemic embolisation is common in patients with dilated cardiomyopathy. Microembolisation as a presenting sign of dilated cardiomyopathy, however, has not been reported before. A 37 year old woman in whom dilated cardiomyopathy presented as arterial microembolisation to the toes is described.

Differentiated perceptions of exertion: part I. mode of integration of regional signals

The mode of sensory integration of differentiated perceptions of exertion from the legs and chest was determined during sub-maximal cycle ergometer exercise. 50 male subjects performed three separate cycle ergometer tests. Power output was held constant at 840 kpm/min., while pedalling rate was randomly set at 40, 60, or 80 rpm. The over-all rating of perceived exertion was significantly lower than the rating for the legs and higher than that for the chest at each pedalling rate. Local signals from the legs dominated the sensory process. Central signals were less pronounced. The mean of the ratings for the legs and chest was slightly but significantly higher than the over-all rating at each pedalling rate. Therefore, the integration process at the superordinate level of sensory processing appeared as a weighted average of the involved regional signals.

Differentiated perceptions of exertion: part II. relationship to local and central physiological responses

Differentiated ratings of perceived exertion in the legs and chest were compared to local and central physiological adjustments during submaximal cycle ergometer exercise. 50 male subjects performed three separate cycle ergometer tests. Power output was held constant at 840 kpm/min., while pedalling rate was randomly set at 40, 60, or 80 rpm. Differentiated reports of exertion from the legs were considered to be local signals and reports from the chest to be central signals. Ratings of exertion for the legs, chest and over-all body were each significantly higher at 40 rpm than 60 or 80 rpm. Heart rate, oxygen uptake, ventilation and respiratory rate were also higher at 40 rpm. Lactic acid, pH, and pCO2 were similar between pedalling rates. Lactic acid did not operate differentially to influence local perceptual signals from the legs. Central measures of respiratory and aerobic metabolic adjustments were consistent with the more intense regional report of chest exertion at 40 rpm.

Perceived exertion and the field-independence--dependence dimension

Perceived exertion responses were compared between field-independent and field-dependent perceivers at three cycle-ergometer pedalling rates. 50 male subjects were classified according to mode of field approach on the basis of their performance on an embedded-figures test. Power output was held constant at 840 kpm/min., while pedalling rate was randomly set at 40, 60, or 80 rpm. Significant differences between the field-independent and -dependent groups were not found at the three pedalling rates for any of the physiological variables or for over-all, legs and chest ratings of perceived exertion. The extent of differentiated psychological functioning did not account for individual differences in perceptual reactance during muscular exertion.

Perceived exertion and stimulus intensity modulation

Perceptual augmentation and reduction were considered contrasting styles of Stimulus Intensity Modulation. Differences in perceived exertion between augmenters and reducers were determined for three cycle ergometer work loads. Subjects were 20 males having similar physiological characteristics. Stimulus Intensity Modulation was determined by kinesthetic figural aftereffect. Augmenters rated their perceptions of physical exertion to be more intense than reducers at 450, 750 and 1050 kpm/min. Differences in physiological responses between augmenters and reducers were not significant at the three work loads. Style of Stimulus Intensity Modulation appeared differentially to influence perceived exertion at the work levels studied.

Influence of pretest waiting time and duration of induction on kinesthetic aftereffect

The influence of pretest hand-resting time and induction time on kinesthetic aftereffect was determined for 22 males and females. Aftereffect was assessed with the apparatus of Koehler and Dinnerstein (1947). Three separate tests of aftereffect were administered. Each was preceded by either a 10-, 20-, or 30-min. hand-resting period. Significant differences in aftereffect were not found between pretest conditions. Scores were also determined for varying induction times at each pretest condition. Induction periods totaling 90-, 180-, and 300-sec. were used. Aftereffect was significantly less pronounced following 90 than 180 sec. of induction for the 10-and 20-min. pretest conditions but was the same following 90, 180, and 300 sec. of induction for the 30-min. condition. Results indicated that less than 300 sec. of induction could be used regardless of the duration of the pretest period. However, because the internal validity of the 180-sec. score was significantly better than the 90-sec. score, it was concluded that at least 180 sec. of induction were needed.