语前聋小儿人工耳蜗植入术后的言语康复

An Approach to the Rehabilitation of Prelingually Deaf Children After Cochlear Implantation Zheng Xiujin(Medical Psychology) Directed by Professor Yin WenGang Abstract Objective: To sum up the acquirement rule of speech and language capability which is for the prelingually deaf children after cochlear implantation by listening and language rehabilitation training and to investigate the factors that affect rehabilitation speed. Method: Sixty-four children received a cochlear implant at the age of 2 to 5 years from 2001 to 2005. They begin to be trained under group pattern after switch on 1 month. The whole training program lasted more than 7 months; after that, according to the teacher’s plan the training program was to be continued at home. Result: The period is 108±7.7 days that they can pronounce correctly 50 percent of all of simple-finals and compound-finals, the period is 115.0±7.8 days that they begin auditory repeating, the period is 135.3±10.9 days that they can speech the first specific word independently and the period is 200.3±13.9 days that they can speak 70 words and come into tri-gamut-word and two-word sentence period. The patient that is the group at the age of 2-3 years can take part in normal kindergarten after switch on about 10 months. There are no significant differences in various grades of speech-language development with different age groups and so do with different sex groups. There are significant differences in various grade of speech-language development with various IQ group (P<0.01) and so do with using and not using hearing aids before implantation. Conclusion: From the research we find that the speech and language development sequence is the same level between the prelingually deaf children of 2 to 5 years who received cochlear implant after speech training and normal children and which are stages of uncomplicated sound production, continuous syllabic (babbling), speech sprout, single-word utterances and two-word utterances in proper order. The time is short significantly and the reason is that cognition capability is enhanced along with the increase of age. The intelligence is main factor that affect rehabilitation speed and the speed in the group of high IQ is faster than common IQ. It is not because of the dominance cognition of the senior group that makes the increasing of the rehabilitation, it even makes slowly. The reason of which is that the senior group are exposed the language environment too late to achieve speech and language development. So we should perform an operation and training early. The effectiveness of rehabilitation after cochlear implantation is improved by using hearing aids before implantation. The reason is auditory stimulate can be benefit of to deaf children. The rehabilitation speeds in the children at the age of 2 to 5 years have nothing to do with sex. Key words: cochlear implant; speech therapy; paediatric rehabilitation

VEGF-induced retinal angiogenic signalling is critically dependent on Ca2+ signalling via Ca2+/calmodulin-dependent protein kinase II

Purpose. The authors conducted an in vitro investigation of the role of Ca2+-dependent signaling in vascular endothelial growth factor (VEGF)-induced angiogenesis in the retina.

Methods. Bovine retinal endothelial cells (BRECs) were stimulated with VEGF in the presence or absence of 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA-AM; intracellular Ca2+ chelator), U73122 (phospholipase C (PLC) inhibitor), xestospongin C (Xe-C), and 2-aminoethoxydiphenyl borate (2APB) (inhibitors of inositol-1,4,5 triphosphate (IP3) signaling). Intracellular Ca2+ concentration ([Ca2+]i) was estimated using fura-2 Ca2+ microfluorometry, Akt phosphorylation quantified by Western blot analysis, and angiogenic responses assessed using cell migration, proliferation, tubulogenesis, and sprout formation assays. The effects of the Ca2+/calmodulin-dependent protein kinase II (CaMKII) inhibitor KN93 were also evaluated on VEGF-induced Akt signaling and angiogenic activity.

Results. Stimulation of BRECs with 25 ng/mL VEGF induced a biphasic increase in [Ca2+]i, with an initial transient peak followed by a sustained plateau phase. VEGF-induced [Ca2+]i increases were almost completely abolished by pretreating the cells with BAPTA-AM, U73122, Xe-C, or 2APB. These agents also inhibited VEGF-induced phosphorylation of Akt, cell migration, proliferation, tubulogenesis, and sprouting angiogenesis. KN93 was similarly effective at blocking the VEGF-induced activation of Akt and angiogenic responses.

Conclusions. VEGF increases [Ca2+]i in BRECs through activation of the PLC-IP3 signal transduction pathway. VEGF-induced phosphorylation of the proangiogenic protein Akt is critically dependent on this increase in [Ca2+]i and the subsequent activation of CaMKII. Pharmacologic inhibition of Ca2+-mediated signaling in retinal endothelial cells blocks VEGF-induced angiogenic responses. These results suggest that the PLC/IP3/Ca2+/CaMKII signaling pathway may be a rational target for the treatment of angiogenesis-related disorders of the eye.

Docosahexaenoic Acid Improves the Nitroso-Redox Balance and Reduces VEGF-Mediated Angiogenic Signaling in Microvascular Endothelial Cells

Purpose. Disturbances to the cellular production of nitric oxide (NO) and superoxide (O2-) can have deleterious effects on retinal vascular integrity and angiogenic signaling. Dietary agents that could modulate the production of these signaling molecules from their likely enzymatic sources, endothelial nitric oxide synthase (eNOS) and NADPH oxidase, would therefore have a major beneficial effect on retinal vascular disease. The effect of ?-3 polyunsaturated fatty acids (PUFAs) on angiogenic signaling and NO/superoxide production in retinal microvascular endothelial cells (RMECs) was investigated.

Methods. Primary RMECs were treated with docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA) for 48 hours. RMEC migration was determined by scratch-wound assay, proliferation by the incorporation of BrdU, and angiogenic sprouting using a three-dimensional model of in vitro angiogenesis. NO production was quantified by Griess assay, and phospho-eNOS accumulation and superoxide were measured using the fluorescent probe dihydroethidine. eNOS localization to caveolin-rich microdomains was determined by Western blot analysis after subfractionation on a linear sucrose gradient.

Results. DHA treatment increased nitrite and decreased superoxide production, which correlated with the displacement of eNOS from caveolar subdomains and colocalization with the negative regulator caveolin-1. In addition, both ?-3 PUFAs demonstrated reduced responsiveness to VEGF-stimulated superoxide and nitrite release and significantly impaired endothelial wound healing, proliferation, and angiogenic sprout formation.

Conclusions. DHA improves NO bioavailability, decreases O2- production, and blunts VEGF-mediated angiogenic signaling. These findings suggest a role for ?-3 PUFAs, particularly DHA, in maintaining vascular integrity while reducing pathologic retinal neovascularization.

Evolução da qualidade de cebola armazenada, variedades "Pandero" e "Legend", em função da temperatura e aplicação de hidrazida maleica

A cebola representa no Ribatejo um dos produtos hortícolas de maior peso na economia agrícola regional. Os mercados dos produtos agrícolas são caracterizados por uma oferta contínua ao longo dos doze meses do ano. Actualmente é possível, garantir o fornecimento de cebola num apreciável período de tempo; no entanto, torna-se necessário proceder à sua conservação como forma de garantia de escoamento e regularização do abastecimento ao mercado. O material experimental constou de bolbos das variedades “Pandero” e “Legend” provenientes das plantações dos associados da Agromais e aplicação de um anti-abrolhante (hidrazida maleica), para que se tenha cebola não espigada com 6 meses de armazenamento, mantendo um equilíbrio no mercado durante o ano inteiro. As cebolas foram armazenadas em oito combinações; dois grupos da variedade “Pandero” um tratado outro não com HM, conservados a 4º C. Outros dois grupos da mesma variedade um tratado outro não com HM, conservados a 2,5ºC, repetindo a mesma forma na variedade “Legend”, com uma humidade relativa cerca de 75% (recomendada na conservação da cebola). Foram observadas as seguintes variáveis: podridão; espigamento; defeitos menores; defeitos maiores; defeitos totais e perda de peso. As observações foram realizadas em períodos de 15 em 15 dias, com os seguintes dias de conservação; 0; 16; 30; 46 e 59. O objectivo deste trabalho foi perceber os efeitos da hidrazida maleica e diferentes temperaturas (4 e 2,5ºC) sobre os parâmetros fisiológicos dos bolbos de cebola armazenados. Verificou-se uma menor podridão na temperatura a 2,5ºC, a HM reduziu o espigamento na variedade “Pandero” à temperatura de 4ºC, já sem HM o espigamento foi maior na “Pandero” à temperatura de 4ºC; com o abaixamento da temperatura de 4 para 2,5ºC houve uma redução de 5% no espigamento; os defeitos totais não foram afectados pela temperatura,

Modeling Vegetable Fractals by means of Fractional-order Equations

This paper characterizes four ‘fractal vegetables’: (i) cauliflower (brassica oleracea var. Botrytis); (ii) broccoli (brassica oleracea var. italica); (iii) round cabbage (brassica oleracea var. capitata) and (iv) Brussels sprout (brassica oleracea var. gemmifera), by means of electrical impedance spectroscopy and fractional calculus tools. Experimental data is approximated using fractional-order models and the corresponding parameters are determined with a genetic algorithm. The Havriliak-Negami five-parameter model fits well into the data, demonstrating that classical formulae can constitute simple and reliable models to characterize biological structures.

Double burden malnutrition of preschool children and its association with brain development and milk consumption

Protecting the quality of children growth and development becomes a supreme qualification for the betterment of a nation. Double burden child malnutrition is emerging worldwide which might have a strong influence to the quality of child brain development and could not be paid-off on later life. Milk places a notable portion during the infancy and childhood. Thus, the deep insight on milk consumption pattern might explain the phenomenon of double burden child malnutrition correlated to the cognitive impairments. Objective: Current study is intended (1) to examine the current face of Indonesian double burden child malnutrition: a case study in Bogor, West Java, Indonesia, (2) to investigate the association of this phenomenon with child brain development, and (3) to examine the contribution of socioeconomic status and milk consumption on this phenomenon so that able to formulate some possible solutions to encounter this problem. Design: A cross-sectional study using a structured coded questionnaire was conducted among 387 children age 5-6 years old and their parents from 8 areas in Bogor, West-Java, Indonesia on November 2012 to December 2013, to record some socioeconomic status, anthropometric measurements, and history of breast feeding. Diet and probability of milk intake was assessed by two 24 h dietary recalls and food frequency questionnaire (FFQ). Usual daily milk intake was calculated using Multiple Source Method (MSM). Some brain development indicators (IQ, EQ, learning, and memory ability) using Projective Multi-phase Orientation method was also executed to learn the correlation between double burden child malnutrition and some brain development indicator. Results and conclusions: A small picture of child double burden malnutrition is shown in Bogor, West Java, Indonesia, where prevalence of Severe Acute Malnutrition (SAM) is 27.1%, Moderate Acute Malnutrition (MAM) is 24.9%, and overnutrition is 7.7%. This phenomenon proves to impair the child brain development. The malnourished children, both under- and over- nourished children have significantly (P-value<0.05) lower memory ability compared to the normal children (memory score, N; SAM = 45.2, 60; MAM = 48.5, 61; overweight = 48.4, 43; obesity = 47.9, 60; normal = 52.4, 163). The plausible reasons behind these evidences are the lack of nutrient intake during the sprout growth period on undernourished children or increasing adiposity on overnourished children might influence the growth of hippocampus area which responsible to the memory ability. Either undernutrition or overnutrition, the preventive action on this problem is preferable to avoid ongoing cognitive performance loss of the next generation. Some possible solutions for this phenomenon are promoting breast feeding initiation and exclusive breast feeding practices for infants, supporting the consumption of a normal portion of milk (250 to 500 ml per day) for children, and breaking the chain of poverty by socioeconomic improvement. And, the national food security becomes the fundamental point for the betterment of the next. In the global context, the causes of under- and over- nutrition have to be opposed through integrated and systemic approaches for a better quality of the next generation of human beings.

La familia del paciente en Unidad de Cuidado Intensivo (UCI)

Introducción: Ingresar a la UCI no es una experiencia exclusiva del paciente; implica e involucra directamente a la familia, en aspectos generadores de estrés, estrategias de afrontamiento, temores, actitudes y expectativas, la participación de la familia en el cuidado y el rol del psicólogo. Objetivo: Revisar de los antecedentes teóricos y empíricos sobre la experiencia de la familia en UCI. Metodología: Se revisaron 62 artículos indexados en bases de datos. Resultados: la UCI es algo desconocido tanto para el paciente como para la familia, por esto este entorno acentúa la aparición de síntomas ansiosos, depresivos y en algunos casos estrés post traumático. La muerte es uno de los principales temores que debe enfrentar la familia. Con el propósito de ajustarse a las demandas de la UCI, los familiares exhiben estrategias de afrontamiento enfocadas principalmente en la comunicación, el soporte espiritual y religioso y la toma de decisiones. El cuidado centrado en la familia permite una mejor comunicación, relación con el paciente y personal médico. El papel del psicólogo es poco explorado en el espacio de la UCI, pero este puede promover estrategias de prevención y de rehabilitación en el paciente y su grupo familiar. Discusión: es importante tener en cuenta que la muerte en UCI es una posibilidad, algunos síntomas como ansiedad, depresión pueden aparecer y mantenerse en el tiempo, centrar el cuidado en la familia permite tomar las decisiones basados en el diagnóstico y pronóstico y promueve expectativas realistas. Conclusiones: temores, expectativas, actitudes, estrategias de afrontamiento, factores generadores de estrés permiten explicar y comprender la experiencia de la familia del paciente en UCI.

Anàlisi de la capacitat de regeneració en estadis inicials del desenvolupament en diverses espècies mediterrànies del gènere Quercus

Aquest treball es centra en l'estudi de la regeneració vegetativa en els estadis inicials del desenvolupament de Quercus coccifera, Q. humilis, Q. ilex i Q. suber, analitzant la capacitat de rebrotada després de l'eliminació de la biomassa aèria. S'ha realitzat una descripció, a nivell histològic, de l'ontogènesi del nus cotiledonar des de l'embrió fins a la plàntula de mig any d'edat de Q. coccifera, Q. humilis i Q. ilex. Així mateix, s'ha analitzat el contingut de midó i de nitrogen a la primavera, l'estiu i l'hivern en diferents parts de les plàntules de les quatre espècies, avaluant, alhora, l'efecte de la tala. D'altra banda, també s'ha estudiat la biometria de les glans, la capacitat de germinació i el creixement de les plàntules de les quatre espècies de Quercus. A partir dels resultats s'ha comprovat que les glans de Q. suber, en general, són més grans, tant en diàmetre com en longitud, i tenen un pes superior, mentre que les de Q. ilex són més petites i pesen menys. En les quatre espècies estudiades, el pes de la llavor està determinat per la longitud i el diàmetre, si bé, també hi ha un cert efecte de l'espècie. Amb les dades obtingudes de les tres variables de la gla s'ha calculat una funció discriminant a partir de la qual es pot determinar, amb un alt grau d'encert, a quina espècie pertany una determinada gla coneixent la mida i el pes. En relació a la capacitat de germinació, en Q. coccifera i Q. ilex la germinació depèn del pes de la gla, mentre que en Q. humilis i Q. suber és independent. Així mateix, també s'ha comprovat que el pes de la llavor afecta positivament en el creixement de les plàntules de tres i sis mesos d'edat. Possiblement un major pes de la gla implica un contingut de substàncies de reserva més elevat, i per tant representa un major subministrament de nutrients cap a la planta, repercutint així en el seu creixement inicial. En plàntules de nou mesos d'edat ja no s'ha trobat relació entre el pes de la gla i el creixement de la planta, la qual cosa es podria explicar pel fet que les substàncies de reserva de la llavor s'han esgotat. Pel que fa al creixement de la plàntula, les plàntules de Q. ilex han tingut la major taxa de creixement per quasi totes les variables estudiades. En aquesta espècie, al principi de l'experiment la grandària de les plàntules ha estat baixa, però al final han crescut més que les de les altres espècies. Les plàntules de Q. coccifera han presentat la menor taxa. En les plàntules de les quatre espècies s'ha constatat, també, que la biomassa del sistema radicular és superior a la de l'aeri. Les plàntules de Q. coccifera i Q. humilis han tingut una relació BA/BR (biomassa aèria/biomassa radicular) més baixa que les de Q. ilex i Q. suber. En espècies mediterrànies s'ha relacionat sovint una baixa relació BA/BR com una adaptació a la sequera. No obstant això, Q. humilis és una espècie que viu en zones més humides que la resta d'espècies estudiades. En referència a la regeneració vegetativa, amb aquest estudi es demostra que les plàntules de les quatre espècies tenen una elevada capacitat d'emissió de rebrots, quan s'elimina la biomassa aèria per sobre la zona d'inserció dels cotilèdons. Tanmateix, el grau de supervivència difereix segons l'espècie i la intervenció. Així, per exemple, les plàntules de Q. ilex han presentat una major mortalitat tant en la primera com en la segona tala, mentre que en Q. humilis i Q. suber la supervivència de les plàntules ha disminuït després de talar dues vegades. En el cas de Q. coccifera el grau de supervivència és bastant similar tant en la primera com en la segona intervenció. La tala successiva afecta negativament al vigor dels rebrots en Q. coccifera, Q. humilis i Q. ilex. Ara bé, en el cas de Q. suber s'ha trobat que els rebrots emesos després de talar dues vegades han estat més grans que els obtinguts després d'una sola tala. Després de tallar la biomassa aèria per sobre la zona d'inserció dels cotilèdons, els rebrots s'originen a partir de les gemmes del nus cotiledonar. L'estudi de l'ontogènesi del nus cotiledonar ens ha permès de constatar que el patró de desenvolupament d'aquest en Q. coccifera, Q. humilis i Q. ilex és similar, però difereix del descrit per a Q. suber. En les tres primeres espècies el nus cotiledonar pràcticament no s'allarga i només es desenvolupen gemmes cotiledonars just en l'axil·la del pecíol cotiledonar. En aquest sentit, cal ressaltar que en el cas de Q. coccifera i Q. ilex les gemmes es formen després de germinar la gla, mentre que en Q. humilis i Q. suber són ja presents en l'embrió. Tal i com també s'ha descrit en Q. suber, en l'estadi de plàntula, en Q. coccifera, Q. humilis i Q. ilex a l'axil·la de la gemma cotiledonar proliferen noves gemmes, de tal manera que es formen plaques de gemmes. Les anàlisis del contingut de midó han permès de determinar que el sistema radicular de les plàntules de Q. coccifera, Q. humilis, Q. ilex i Q. suber conté aproximadament un 90% del midó de tota la planta. Concretament de les diferents fraccions del sistema radicular (nus cotiledonar, 11 pimers centímetres de l'arrel i resta de l'arrel) la major concentració de midó es troba ens els 11 primers cm de l'arrel, que en el cas de Q. suber correspon al nus cotiledonar. Quant a les estacions, a l'estiu la concentració de midó de la part aèria i radicular disminueix en Q. coccifera, Q. humilis i Q. ilex, si bé es recuperen a l'hivern. En canvi en el cas de Q. suber els nivells més baixos de midó s'han obtingut a l'hivern. La tala provoca una disminució dels nivells de midó, ja que una part d'aquest és mobilitzat per a la síntesi dels nous brots. En les quatre espècies la major proporció de midó mobilitzat és en els primers 11 cm de l'arrel, és a dir, el nus cotiledonar en el cas de Q. suber. Per tant, amb aquest estudi es reafirma que el nus cotiledonar de Q. suber és un lignotúber. Tanmateix, Q. coccifera, Q. humilis i Q. ilex no presenten cap lignotúber o estructura especialitzada en la rebrotada, si bé el fet de tenir gemmes i substàncies de reserva els confereix igualment una elevada capacitat per rebrotar. En relació al nitrogen, en les quatre espècies el sistema radicular presenta aproximadament el 70% del nitrogen total de la planta. A l'estiu, la concentració de nitrogen del sistema radicular de Q. humilis i Q. suber és més baixa que a l'hivern, mentre que en Q. coccifera i Q. ilex els valors són bastant similars en ambdues estacions. La tala no provoca una davallada dels nivells de midó, això possiblement es degui a que les plàntules van rebre continuament un aport de nitrogen a través de l'aigua de reg.

A maternal influence on the conditioning to plant cues of Aphidius colemani Viereck, parasitizing the aphid Myzus persicae Sulzer

The offspring of parasitoids, Aphidius colemani Viereck, reared on Brussels sprouts and emerging from Myzus persicae Sulzer on a fully defined artificial diet, show no preferences in a four-way olfactometer, either for the odour of the diet, the odour of Brussels sprouts, or the odour of two other crucifers (cabbage and Chinese cabbage). A similar lack of odour preferences is shown when the host aphids are exposed for parasitization (for 48 h) on cabbage, Chinese cabbage or wheat. However, if parasitization occurs on Brussels sprouts, a weak but statistically highly significant response to Brussels sprout odour is observed. Although as many as 30-35% of the parasitoids show no response to any odour, another 35% respond positively to the odour of Brussels sprout compared with responses to the odours of cabbage, Chinese cabbage or wheat of only approximately 10%. An analagous result is obtained when the parent parasitoids are reared on cabbage. In this case, significant positive responses of their offspring to cabbage odour occur only if the 48-h parasitization has occurred also on cabbage. However, with parasitoids from Brussels sprouts parasitizing the aphids for 48 h also on Brussels sprouts, the offspring subsequently emerging from pupae excised from the mummies show no preference for Brussels sprout odour. Thus, although the Brussels sprout cue had been experienced early in the development of the parasitoids, they only become conditioned to it when emerging from the mummy. Both male and female parasitoids respond very similarly in all experiments. It is proposed that the chemical cue (probably glucosinolates in these experiments) is most likely in the silk surrounding the parasitoid pupa, and that the mother may leave the chemical in or around the egg at oviposition, inducing chemical defences in her offspring to the secondary plant compounds that the offspring are likely to encounter.

Phases of dormancy in yam tubers (Dioscorea rotundata)

center dot Background and Aims The control of dormancy in yam (Disocorea spp.) tubers is poorly understood and attempts to shorten the long dormant period (i.e. cause tubers to sprout or germinate much earlier) have been unsuccessful. The aim of this study was to identify and define the phases of dormancy in Dioscorea rotundata tubers, and to produce a framework within which dormancy can be more effectively studied. center dot Methods Plants of 'TDr 131' derived from tissue culture were grown in a glasshouse simulating temperature and photoperiod at Ibadan (7 degrees N), Nigeria to produce tubers. Tubers were sampled on four occasions: 30 d before shoot senescence (149 days after planting, DAP), at shoot senescence (179 DAP), and twice during storage at a constant 25 degrees C (269 and 326 DAP). The development of the apical shoot bud was described from tissue sections. In addition, the responsiveness of shoot apical bud development to plant growth regulators (gibberellic acid, 2-chloroethanol and thiourea) applied to excised tuber sections was also examined 6 and 12 d after treatment. center dot Key Results and Conclusions Three phases of tuber dormancy are proposed: Phase I, from tuber initiation to the appearance of the tuber germinating meristem; Phase II, from the tuber germinating meristem to initiation of foliar primordium; and Phase III, from foliar primordium to appearance of the shoot bud on the surface of the tuber. Phase I is the longest phase (approx. 220 d in 'TDr 131'), is not affected by PGRs and is proposed to be an endo-dormant phase. Phases II and III are shorter (< 70 d in total), are influenced by PGRs and environmental conditions, and are therefore endo-/eco-dormant phases. To manipulate dormancy to allow off-season planting and more than one generation per year requires that the duration of Phase I is shortened.

Effect of harvest date on the dormancy period of yam (Dioscorea rotundata)

Tuber dormancy enables yams to survive in the ground during the dry season and post-harvest storage. Three clones of Dioscorea rotundata were harvested after five intervals and then stored in a cooler (20.6°C) or at ambient temperature (27.8°C). The time from harvest to sprouting was shorter as harvest was delayed. The period from sowing to sprouting for each clone was similar for tubers harvested from 140 days after planting, but tubers harvested earlier took longer to sprout. The cooler temperature delayed sprouting. Tubers of two clones sprouted after only 70 days of crop growth. If the dormancy period of these young tubers can be broken, the generation time of yam crop improvement programmes could be considerably reduced.

Artificial diet for aphids - thirty years' experience

Myzus persicae (Sulzer) was reared continuously for over thirty years (until it died out in December 2008) on a totally defined synthetic artificial diet, the procedure for which is described. Development time was extended on diet compared with rearing on Brussels sprout plants (Brassica oleracea L. var. gemmifera L.), and generation time was further increased by an added pre-reproductive period of 4 days. Fecundity was reduced by about two-thirds, and mean relative growth rate in weight (MRGR) was only 60% in comparison with plant-reared aphids. Applying 2 kg/cm(2) pressure to a 10% sucrose solution extended the adult longevity of Aphis fabae Scopoli by less than I day. In contrast, a short experience of half-strength diet Caused a sharp rise in honeydew excretion by A. fabae for several hours, and alternating full-strength diet with diluted diets (including water) Caused a greater weight increase. The poor performance of aphids on diet thus seems to have a behavioural rather than a mechanical explanation. The diet, designed to give optimal performance of the aphids, has proved not to be useful for nutritional studies, as any change is deleterious. Areas of aphid research where the diet has been useful, however, are studies on repellents/attractants/toxins, role of symbionts, maintenance of genotype collections, work on parasitoid behaviour in relation to plant chemistry, and collection of aphid saliva.

Phases of dormancy in yam tubers (Dioscorea rotundata)

Background and Aims The control of dormancy in yam (Disocorea spp.) tubers is poorly understood and attempts to shorten the long dormant period (i.e. cause tubers to sprout or germinate much earlier) have been unsuccessful. The aim of this study was to identify and define the phases of dormancy in Dioscorea rotundata tubers, and to produce a framework within which dormancy can be more effectively studied. center dot Methods Plants of 'TDr 131' derived from tissue culture were grown in a glasshouse simulating temperature and photoperiod at Ibadan (7 degrees N), Nigeria to produce tubers. Tubers were sampled on four occasions: 30 d before shoot senescence (149 days after planting, DAP), at shoot senescence (179 DAP), and twice during storage at a constant 25 degrees C (269 and 326 DAP). The development of the apical shoot bud was described from tissue sections. In addition, the responsiveness of shoot apical bud development to plant growth regulators (gibberellic acid, 2-chloroethanol and thiourea) applied to excised tuber sections was also examined 6 and 12 d after treatment. center dot Key Results and Conclusions Three phases of tuber dormancy are proposed: Phase I, from tuber initiation to the appearance of the tuber germinating meristem; Phase II, from the tuber germinating meristem to initiation of foliar primordium; and Phase III, from foliar primordium to appearance of the shoot bud on the surface of the tuber. Phase I is the longest phase (approx. 220 d in 'TDr 131'), is not affected by PGRs and is proposed to be an endo-dormant phase. Phases II and III are shorter (< 70 d in total), are influenced by PGRs and environmental conditions, and are therefore endo-/eco-dormant phases. To manipulate dormancy to allow off-season planting and more than one generation per year requires that the duration of Phase I is shortened.

Physiological, biochemical and transcriptional analysis of onion bulbs during storage

Abstract: During the transition from endo-dormancy to eco-dormancy and subsequent growth, the onion bulb undergoes the transition from sink organ to source, to sustain cell division in the meristematic tissue. The mechanisms controlling these processes are not fully understood. Here, a detailed analysis of whole onion bulb physiological, biochemical and transcriptional changes in response to sprouting is reported, enabling a better knowledge of the mechanisms regulating post-harvest onion sprout development. Biochemical and physiological analyses were conducted on different cultivars ('Wellington', 'Sherpa' and 'Red Baron') grown at different sites over 3 years, cured at different temperatures (20, 24 and 28 degrees C) and stored under different regimes (1, 3, 6 and 6 1 degrees C). In addition, the first onion oligonucleotide microarray was developed to determine differential gene expression in onion during curing and storage, so that transcriptional changes could support biochemical and physiological analyses. There were greater transcriptional differences between samples at harvest and before sprouting than between the samples taken before and after sprouting, with some significant changes occurring during the relatively short curing period. These changes are likely to represent the transition from endo-dormancy to sprout suppression, and suggest that endo-dormancy is a relatively short period ending just after curing. Principal component analysis of biochemical and physiological data identified the ratio of monosaccharides (fructose and glucose) to disaccharide (sucrose), along with the concentration of zeatin riboside, as important factors in discriminating between sprouting and pre-sprouting bulbs. These detailed analyses provide novel insights into key regulatory triggers for sprout dormancy release in onion bulbs and provide the potential for the development of biochemical or transcriptional markers for sprout initiation. Evidence presented herein also suggests there is no detrimental effect on bulb storage life and quality caused by curing at 20 degrees C, producing a considerable saving in energy and costs.

Tales of the unexpected: research discoveries that occurred by accident

Data from four experimental research projects are presented which have in common that unexpected results caused a change in direction of the research. A plant growth accelerator caused the appearance of white black bean aphids, a synthetic pyrethroid suspected of enhancing aphid reproduction proved to enhance plant growth, a chance conversation with a colleague initiated a search for fungal DNA in aphids, and the accidental invasion of aphid cultures by a parasitoid reversed the aphid population ranking of two Brussels sprout cultivars. This last result led to a whole series of studies on the plant odour preferences of emerging parasitoids which in turn revealed the unexpected phenomenon that chemical cues to the maternal host plant are left with the eggs at oviposition. It is pointed out that, too often, researchers fail to follow up unexpected results because they resist accepting flaws in their hypotheses; also that current application criteria for research funding make it hard to accommodate unexpected findings.