Oral health among institutionalised elderly in Zagreb, Croatia

Objective: A survey of dental health status was conducted in the institutionalised elderly in Zagreb, Croatia in order to assess the dental and oral health of the elderly population. Participants: In 139 institutionalised elderly from a single nursing home in Zagreb, dental and oral status was registered according to World Health Organization criteria. There were 108 (77.7%) female and 31 (22.3%) male subjects aged 58–99 years. Results: The results showed that 45.3% of the interviewed persons were totally edentulous in both jaws. A significant increase in prevalence of edentulousness with the increasing age was recorded. The mean decayed, missing and filled teeth number was 27. The average number of teeth with caries was 1.03 per person, the number of the teeth extracted was 6.9 per person and teeth with fillings 0.74 per person. The average number of teeth with root caries was 0.17. Approximately 9 teeth per person were in need of treatment. Filled teeth were found 25.9% of subjects and decayed teeth in 30.9%. The mean number of remaining sound teeth, decayed teeth and residual roots in the elderly decreased with increasing age. Complete periodontal treatment was required in 5.8% of the participants and no significant differences between genders in periodontal status could be noticed. Conclusion: The results of this study suggest poor dental health in this group of the institutionalised elderly and the necessity of improving and implementing some special features in the dental health services programs for the institutionalised elderly.     

Caries and periodontal disease of the elderly in Pomerania, Germany: results of the Study of Health in Pomerania

Objective: The aim of this study was to describe the oral health status of older adults living in north‐eastern Germany. Materials and Methods: Representative samples of adults aged 60 years or older were examined as part of Study of the Health in Pomerania, a cross‐sectional, population‐based study. Data on 1446 subjects aged 60–79 years were evaluated for coronal caries using the decayed/missing/filled teeth (DMFT) index, root caries using the root caries index (RCI), calculus, plaque, bleeding on probing, pocket depth and attachment loss. Results: The prevalence of edentulousness varied from 16% in the 60–65‐year‐old group to 30% in the 75–79‐year‐old group, whereas the median number of remaining natural teeth per subject varied from 14 in the youngest age group (60–65 years) to one in the oldest (75–79 years). Among subjects aged 60–69 years, a quarter (26%) of the teeth examined had coronal restoration against 17% in the oldest age group (70–79 years). Coronal caries was found in 2% of the teeth in both age groups. Among teeth with gingival recession, 6% had fillings on root surfaces and 2% had root caries, irrespective of age. In all, 11% of the subjects had at least one untreated coronal lesion and 27% had at least one untreated root caries lesion. Plaque score, calculus score and bleeding on probing were higher in the oldest age group (70–79 years). The prevalence of periodontal disease expressed as the presence of at least one periodontal pocket of 4 mm and more, was higher in men and among the younger subjects (men aged 60–69 years: 85% vs. 71% in 70–79‐year‐old men; women aged 60–69 years: 71% vs. 62% in 70–79‐year‐olds). The prevalence of attachment loss of 3 mm or more followed a similar pattern. Conclusions: It seems therefore that in this population, the major oral health concern is related to caries and the small number of teeth retained among the dentate subjects.     

Number of teeth and risk of root caries

Objective: This study aimed to investigate the association between number of natural teeth and prevalence of root caries. Design: A cross‐sectional design was adopted. A stratified multi‐stage purposive sampling method was used to select a wide range of elderly people from all social classes, educational levels and sexes. Data was collected through interviews and clinical examinations. Setting: Urban area in Chiang Mai‐Thailand. Participants: 549 elderly dentate aged 60‐74 years. Main Outcome Measures: Teeth with decay and filled roots (DF‐T). Results: The prevalence of root caries was 18.2% with a mean DF‐T of 0.58 (S.D. 2.02). Results of multiple logistic regression showed that number of teeth, DMF‐S scores, sex, and socio economic factors were statistically significantly associated with root caries (P<0.05). Adjusted odds ratios demonstrated a 14% increase in the chance of having root caries when the number of teeth increased one unit. Similarly, a 3% increase was observed for each unit increase in the DMF‐S scores (p<0.001). Being male, having more than four years of education and earning more than 1500 baht/month increased the chances of root caries by 76%, 139% and 85% respectively (p<0.001). Recession and age were not statistically significantly associated with root caries. Conclusions: Having more teeth, higher DMF‐S scores, earning more than 1500 baht/month, having more than 4 years of education and being male increased the likelihood of having root caries.     

Prosthetic crowns and other clinical risk indicators of caries among old-old Swedish adults: findings from the KEOHS Project. Kungsholmen Elders Oral Health Study

Objectives: The Kungsholmen Elders Oral Health Study (KEOHS) evaluated the oral health status of generally healthy, community‐dwelling persons over the age of 80 living in Kungsholmen, Sweden. This paper explored possible clinical risk indicators of coronal and root caries among the KEOHS subjects. Design: In this cross‐sectional study, dentate KEOHS subjects received a caries assessment using defined visual, tactile criteria. Setting: Examinations were carried out in two local clinics by standardized examiners. Subjects: One hundred twenty‐nine dentate persons were examined. Main Outcome Measures: The examination identified decayed and filled surfaces, prosthetic crowns, and missing teeth. Results: More root than coronal surfaces had untreated decay, and secondary root caries contributed the greatest number of decayed surfaces. Ninety percent of the examined dentate subjects had at least one prosthetic crown. Root surfaces exposed to crown margins were more likely to have caries than root surfaces not so exposed, particularly among women. The presence of untreated coronal caries (yes/no) was positively associated with having untreated root caries and an intermediate number (14–20) of teeth, but inversely associated with having 4+ prosthetic crowns. Active root caries (yes/no) was positively associated with having untreated coronal caries, 14–20 teeth, and 4+ prosthetic crowns. Nearly 20% of identified root lesions were present at or below the gingival margin, and most (88%) were secondary caries associated with crown margins (65%) or other restorations (23%). Conclusions: Our findings suggest that some dental characteristics, including the presence of prosthetic crowns, are risk indicators for the presence of untreated coronal and root caries.     

多效唑浸种对渗透胁迫下玉米根边缘细胞发生的影响

以‘农大108’玉米种子为材料,采用不同浓度(50、100、150、200、250、300、350 mg·L-1)的多效唑溶液进行浸种处理,研究其对渗透胁迫(20％ PEG-6000)下玉米种子萌发、根系生长和根系边缘细胞数目、活性及黏胶层厚度的影响.结果表明:与对照相比,渗透处理抑制了玉米种子露白与根系生长,增加了边缘细胞数目与黏胶层厚度.预先用多效唑浸种后再进行渗透胁迫处理进一步降低了主根的长度,但增加侧根的生长而使根系鲜重增加,进一步增加了根边缘细胞黏胶层厚度,在一定程度上减少了由于渗透胁迫造成的边缘细胞数目的增加程度.无论是渗透处理还是预先用多效唑浸种处理对边缘细胞活性的影响均不大.可见,多效唑浸种能够增加玉米根系的抗旱能力与边缘细胞黏胶层厚度的增加有关,而与边缘细胞数目、活性的关系不大;多效唑浸种溶液的适宜浓度范围为200～250 mg·L-1.     

The prevalence of root surface caries amongst Irish adults

In a national survey of adult dental health conducted in the Republic of Ireland in 1989/90 a total of 1,527 subjects aged 25 and older were examined for root surface caries. It was found that the prevalence of root surface caries was highest in older age groups and also amongst males, residents of non-fluoridated communities and those earning low incomes. Tooth loss masked the potential prevalence of root surface caries. With more persons retaining their natural teeth into middle and old age the prevalence of root surface caries is likely to increase in the future.     

Variation in the developing root cone angle of the permanent mandibular teeth of modern man and certain fossil hominids

The radiographic appearance of the developing root apex of 461 mandibular teeth was studied using ellipsopantomographs of 77 individuals. The angle formed by the mesial and distal aspects of the developing root cone was measured for each quarter of root development in the permanent mandibular teeth of each subject. Large values for this angle in the more coronal part of the root gradually decreased towards the root apex where values were small in all teeth studied. This gradual decrease in the angle of the developing root cone is concordant with the faster increase in root length but slower rates of dentinogenesis reported for the apical region of human teeth in the literature, as the decrease is likely to reflect the increasing numbers of odontoblasts that become involved in root formation as it proceeds apically. The developing root cone angles of one of the five fossil hominid specimens studied (KMN-ER 820) fall outside the range for the developing root cone angle of the developing premolar and permanent second molar roots in modern Homo sapiens and is evidence of a faster rate of root elongation than is typical for modern man.     

Influence of Age and Hypertension Treatment-time on Ambulatory Blood Pressure in Hypertensive Patients

Some studies based on ambulatory blood pressure (BP) monitoring (ABPM) have reported a reduction in sleep-time relative BP decline towards a more non-dipping pattern in the elderly, but rarely have past studies included a proper comparison with younger subjects, and no previous report has evaluated the potential role of hypertension treatment time on nighttime BP regulation in the elderly. Accordingly, we evaluated the influence of age and time-of-day of hypertension treatment on the circadian BP pattern assessed by 48-h ABPM. This cross-sectional study involved 6147 hypertensive patients (3108 men/3039 women), 54.0?±?13.7 (mean?±?SD) yrs of age, with 2137 (978 men/1159 women) being ≥60 yrs of age. At the time of study, 1809 patients were newly diagnosed and untreated, and 4338 were treated with hypertension medications. Among the later, 2641 ingested all their prescribed BP-lowering medications upon awakening, whereas 1697 ingested the full daily dose of ≥1 hypertension medications at bedtime. Diagnosis of hypertension in untreated patients was based on ABPM criteria, specifically an awake systolic (SBP)/diastolic (DBP) BP mean ≥135/85?mm Hg and/or an asleep SBP/DBP mean ≥120/70?mm Hg. Collectively, older in comparison with younger patients were more likely to have diagnoses of microalbuminuria, chronic kidney disease, obstructive sleep apnea, metabolic syndrome, anemia, and/or obesity. In addition, the group of older vs. younger patients had higher glucose, creatinine, uric acid, triglycerides, and fibrinogen, but lower cholesterol, hemoglobin, and estimated glomerular filtration rate. In older compared with younger patients, ambulatory SBP was significantly higher and DBP significantly lower (p?<?.001), mainly during the hours of nighttime sleep and initial hours after morning awakening. The prevalence of non-dipping was significantly higher in older than younger patients (63.1% vs. 41.1%; p?<?.001). The largest difference between the age groups was in the prevalence of a riser BP pattern, i.e., asleep SBP mean greater than awake SBP mean (19.9% vs. 4.9% in older vs. younger patients, respectively; p?<?.001). The sleep-time relative SBP decline was mainly unchanged until ～40 yrs of age, and then significantly and progressively decreasing with increasing age at a rate of .28%/yr (p?<?.001), reaching a minimum value of 4.38%?±?.47% for patients ≥75 yrs of age. Treated compared with untreated patients showed lower awake and asleep SBP means, although the predictable changes of SBP and DBP with age were equivalent in both groups. As a consequence, there were no significant differences between untreated and treated patients in the changes of the sleep-time relative SBP and DBP declines with age. Additionally, the asleep SBP and DBP means were significantly lower and the sleep-time relative SBP and DBP declines significantly higher at all ages in patients ingesting ≥1 BP-lowering medications at bedtime as compared with those ingesting all medications upon awakening. Our findings document a significantly elevated prevalence of a blunted nighttime BP decline with increasing age ≥40 yrs. The prevalence of a riser BP pattern, associated with highest cardiovascular risk among all possible BP patterns, was 4 times more prevalent in patients ≥60 yrs of age than those <60 yr of age. Most important, there was an attenuated prevalence of a blunted nighttime BP decline at all ages when ≥1 hypertension medications were ingested at bedtime as compared with when all of them were ingested upon awakening. These findings indicate that older age should be included among the conditions for which ABPM is recommended for proper cardiovascular risk assessment. (Author correspondence: rhermida@uvigo.es)     

A Cone-Beam Computed Tomographic Study on Mandibular First Molars in a Chinese Subpopulation

The purpose of this study was to conduct a cone-beam computed tomographic (CBCT) investigation on the root and canal configuration of the mandibular first molars, especially the morphology of the disto-lingual (DL) root, in a Chinese subpopulation. A total of 910 CBCT images of the mandibular first molars were collected from 455 patients who underwent CBCT examinations as a preoperative assessment for implants or orthodontic treatment. The following information was analyzed and evaluated: tooth position, gender, root and root canal number per tooth, root canal type of the mesial root(s) and distal root(s), angle of the DL root canal curvature, distance between two distal canal orifices in the teeth with DL root, and angle of disto-buccal canal orifice–disto-lingual canal orifice–mesio-lingual canal orifice (DB-DL-ML). Most of the mandibular first molars (64.9%, n = 591) had two roots with three root canals, and most of the mesial root canals (87.7%, n = 798) were type VI. The prevalence of the DL root was 22.1% (n = 201). The right side had a higher prevalence of DL root than the left side (p<0.05). Additionally, the curvature of the DL root canal were greater in the bucco-lingual (BL) orientation (30.10°±14.02°) than in the mesio-distal (MD) orientation (14.03°± 8.56°) (p<0.05). Overall there was a high prevalence of DL root in the mandibular first molars, and most of the DL roots were curved in different degrees. This study provided detailed information about the root canal morphology of the mandibular first molars in a Chinese subpopulation.     

黄淮平原冬小麦不同品种根系生长差异

选择黄淮平原地区当前主推品种郑麦9023,以及早期引进品种阿勃和丰产3号为材料,利用微根管技术,研究冬小麦活根长和根直径径级的分布动态,以及以活根长为基础的净生长速率的变化规律.结果表明：根直径为0.05～0.25 mm的细根是冬小麦根系的主要组成部分,根直径≤0.5 mm的细根占活根长的98%以上;冬小麦的平均根直径随着生育进程不断变化,其变化范围为0.15～0.22 mm,不同品种之间没有显著差异;活根长与根尖数呈显著正相关,表明根尖数是活根长增加的主导因素;返青期到拔节期是冬小麦根系生长最旺盛的时期,阿勃和丰产3号具有较长时期的根系增长活力,郑麦9023自拔节期以后根直径≥0.1 mm的细根根尖数占总根尖数的比例有所上升,这有利于提高生育后期根系抗性和保证根系活性稳定,以满足籽粒灌浆的需要.     

Oxygen requirements and mass transfer in hairy-root culture

Oxygen mass transfer in clumps of Atropa belladonna hairy roots was investigated as a function of root density and external flow conditions. Convection was the dominant mechanism for mass transfer into root clumps 3.5 to 5.0 cm in diameter; Peclet numbers inside the clumps ranged from 1.4 x 10(3) to 7.1 x 10(4) for external superficial flow velocities between 0.4 and 1.4 cm s(-1). Local dissolved-oxygen levels and rates of oxygen uptake were measured in aflow chamber and in bubble column and stirred bioreactors. When air was used as oxygen source, intraclump dissolved-oxygen tensions ranged from90% to 100% air saturation at high external flow velocity andlow root density, to less than 20% air saturation in dense root clumps. Specific oxygen-uptake rate declined with increasing root density. When external boundary layers around individual roots were eliminated byforcing liquid through the clumps at superficial velocities between 0.2 and1.0 cm s(-1), internal dissolved-oxygen tension was maintained at 95% to 100% air saturation and rate of oxygen uptake at 1.6 x 10(-6) g g(-1) s(-1) dry weight. Liquid culture of single A. belladonna hairy roots was used to investigate the effect of dissolved-oxygen tensionon root growth and morphology. Total root length and number of root tips increased exponentially at oxygen tensions between 70% and 100%air saturation. Specific growth rate increased with oxygen tension up to 100% air saturation; this result demonstrates that hairy roots aeratedwithout oxygen supplementation are likely to be oxygenlimited. No growth occurred at 50% air saturation. Growth of hairy roots proceeded with an average length per tip of about 1 cm; this value was essentially independent of dissolved-oxygen tension between 70% and 100% air saturation. (c) 1994 John Wiley & Sons, Inc.     

Oral health status of the elderly in a residential home in Turkey

Objectives: To determine the oral health status and treatment needs of elderly residents of a residential home in Ankara, Turkey. Background: Little is known about oral health problems of elderly living in the institutions. Methods: Among 216 elderly, 193 of them were interviewed and were clinically examined according to WHO criteria. Age, gender, educational and occupational status, oral hygiene practices, dental insurance, access to dental care and systemic diseases were recorded using a structured questionnaire. Coronal and root caries, periodontal disease, dental status and related treatment needs were assessed by two calibrated dentists. Results: The mean age of the subjects were 75.2 ± 8.3 in males, 79.1 ± 7.9 in females; 32.6% of subjects were dentate and the mean number of teeth was 3.7 ± 7.0 (median = 0). A functional dentition was present in 7.3% of subjects (≥20). The mean decayed, missing and filled teeth (DMFT) was 29.3 ± 5.8 (median = 32) and mean root caries was 2.2 ± 3.1 (median = 1.0). The major reason for tooth extraction was dental caries. Of the subjects, 20.7% had at least one untreated coronal caries and 18.1% root caries. The assessment of periodontal status according to CPI revealed that only four persons had nine healthy sextants with the score of ‘0’. Edentulousness was 67.4% while 11.9% of them lacked denture in both jaws. Conclusion: The results illustrated poor dental health and showed extremely high demand for the dental health services programmes for the elderly living in these institutions.     

Taurodontism, an isolated trait associated with syndromes and X-chromosomal aneuploidy.

A review of the literature on teeth with enlarged pulp chambers and apical displacement of the bifurcation or trifurcation of roots (taurodontism) and investigation of the association of this trait with X-chromosomal aneuploidy shows that: (1) Taurodontism is not a rare trait in modern man, as indicated by the majority of recent reports, but occurs in approximately 2.5% of adult Caucasians. (2) Taurodontism occurs in syndromes, particularly in those having an ectodermal defect. (3) Among 12 patients showing taurodontic teeth radiographically, all had normal karyotypes. (4) Among 12 patients showing various combinations of X-chromosomal aneuploidy, 11 had taurodontic molars. (5) Patients with a female habitus and X-chromosomal aneuploidy as well as patients with a male habitus and X-chromosomal states have taurodontic teeth. (6) There is no simple association of the degree of taurodontism and the number of X chromosomes, but, in general, patients with the more severe forms of the trait--meso- or hypertaurodontism--are more likely to have X-chromosomal aneuploidy. While taurodontism may be viewed as an extension of a continuous trait of pulp chamber size, the extreme shape may arise when conditions disturbing the epithelial-derived root sheath produce a generalized amplified instability of development, as has been suggested from tissue culture studies of X-chromosomal aneuploid cells.     

Development of the root crown in some conifers

Summary Large and small stumps of 3 spruce species, a pine, a fir and hemlock were pulled up from 15 year plantations. Roots originating from the root crown were counted (<0.5 cm) or, if larger, their diameters were measured, taper, eccentricity, compass bearing, inclination, position on the rootstock and basal age (by annual rings). The sequence of events leading to the developed skeletal root system was reconstructed. Hypotheses to account for the distinct populations of roots were examined. In all species, major roots originated between 2 and 7 yrs after planting and grew thicker and more eccentric at their bases than minor roots of the same age. Positively geotropic roots were distinct from plagiogeotropic roots.     

Traditional CVD risk factors and socio-economic deprivation in Roma minority population of Croatia

Researches into health inequalities consistently show disadvantages in health status, morbidity and mortality for various ethnic minority groups. Current knowledge about prevention of cardiovascular diseases (CVD) mainly derives from studies carried out in populations of European origin while the evidences involving Roma population are scarce. Roma, an ethnic minority of northern Indian origin, live in many countries throughout the world and are well known for preserved traditions and resistance to assimilation. They are most often marginalized economically, spatially, politically and in terms of culture. In order to assess the health status and health-related lifestyle attributes, a multidisciplinary anthropological and epidemiological community-based study was carried out including a total of 423 members of the Bayash Roma minority population living in two regions of Croatia (144 men and 279 women, aged 18-84 yrs). Hypertension (HT) was found in 24.8% Bayash Roma (21.5% men and 26.5% women) using standard diagnostic criteria (i.e. BP > or = 140/90 mm Hg or taking antihypertensive therapy). The prevalence increases from 5.9% in the age group 18-34 yrs; 35.0% in the age group 35-64 yrs, and 51.4% in the age group 65+ yrs. The prevalence of hypertension in the Bayash Roma is almost half of the magnitude of what is usually reported for the general population of Croatia. It is also lower when compared with other European populations and this finding is not due to comparatively younger average age of the Bayash sample. The significant association of hypertension with age and BMI was confirmed in this study and the importance of non-traditional SES-related CVD risk factors was highlighted. Smoking is a part of traditional Roma life-style and with 70% of smokers almost the entire population is equally exposed to this risk factor in their family environment. Since homogenously distributed, this risk factor did not show to be a significant predictor of hypertension. The extent to which hypertension is influenced by traditional CVD risk factors as well as by some SES indicators was also assessed using a forward stepwise method of the multivariate logistic analysis. Each risk factor was explored as quantitative variable as well as qualitative one using various cut-offs. The best model showed to be the one having age and BMI presented as quantitative variables and sex, region, smoking status, income and schooling years as categorical ones; with cut-off 3 for number of income sources and 8 for the number of schooling years. In spite of the low prevalence of hypertension, the presented results are showing that Bayash Roma are bearing a high CVD risk factors load. We expect that with westernization of their life-style and along with increase of the economic power, the proportion of CVD in population of Bayash Roma will also increase. Therefore, it is important to recognize the need for early cardiovascular disease risk factors prevention in this minority population.     

移植胚胎数目对高龄不孕患者IVF—ET结局的影响

目的：探讨移植胚胎数目对高龄不孕患者IVF—ET结局的影响。方法：根据移植胚胎个数将年龄超过35岁的不孕患者338个周期分为单胚胎移植组（I组）,2个胚胎移植组（Ⅱ组）,3个胚胎移植组（Ⅲ组）。分析患者IVF治疗情况并按年龄分层比较三组患者的IVF-ET结局。结果：高龄不孕患者行IVF,随年龄增加,获卵数、优质胚胎率和临床妊娠率降低,流产率呈增高趋势。Ⅰ组的妊娠率9．43％,显著低于Ⅱ组（24．24％）和Ⅲ组（31．37％）（P〈0．05）。对于40岁以下的患者,移植3个胚胎的妊娠率与移植2个胚胎差无异,但显著高于移植1个胚胎（P〈0．05）。增加40岁以上患者移植胚胎的数目,妊娠率未出现有统计学意义的升高。三组的胚胎种植率分别为9．43％,12．12％和12．2％,无统计学差异。Ⅲ组中多胎率12．5％（6／48）,其中35-36岁年龄段多胎率16．67％（5／30）。结论：高龄不孕患者可移植的胚胎数目随年龄增加和获卵数目降低而降低。其中较年轻者（35-36岁年龄段）,移植3个胚胎,对妊娠率提高无明显效果,但多胎发生显著增加。     

Factors associated with remaining teeth of older adults in the state of São Paulo,Brazil, 2002

Objectives: The objective of this study was to verify the association between the number of teeth present with socio-demographic and economic variables and with the access to dental services and self-perception of oral health among the elderly. Materials and Methods: The sample was composed of individuals from 65 to 74 years of age, which was representative of the state of São Paulo (n = 781). In this study, the analysis of data considered dentate elderly only, who were divided into two groups: those with one to 19 teeth and those with 20 teeth or more. The chi-squared test was used in the bivariate analysis and the logistic regression was also performed (p < 0.05). Results: Among the 313 dentate elderly, 235 (75.1%) presented one to 19 teeth. The average number of teeth was 9.5 for the elderly with fewer teeth and 25 for those with more teeth. In the bivariate analysis, all variables related to the access to dental services were associated and the chances of having less teeth was among elderly who did not visit the dentist for a long time and among those who sought public dental services and did not receive information on how to avoid oral problems. In addition, the elderly who classified their speech as not good were those who presented with fewer teeth. Conclusion: Most subjects presented one to 19 teeth and this fact was directly associated, among others factors, to the unsatisfactory perception that they reported in relation to their speech and to the too long period without visiting the dentist.     

氮肥处理对氮素高效吸收水稻根系性状及氮肥利用率的影响

2011—2012年在土培条件下,以氮素吸收效率差异较大的15个常规籼稻为供试材料,研究氮肥运筹对不同氮效率品种根系性状、成熟期吸氮量及氮肥利用率的影响,分析影响氮高效水稻氮素吸收的主要根系性状。结果表明:(1)各氮肥处理下,成熟期吸氮量均表现为氮高效品种氮中效品种氮低效品种。适量增施氮肥及基肥+促花肥处理有利于氮高效品种吸氮量的增加,氮素吸收受品种、氮肥处理的显著影响。(2)在施氮量处理下,氮高效品种单株不定根数、单株根干重、单株不定根总长大或较大,单株根活力在常氮(N2)、高氮(N3)处理下有一定的优势;在施氮时期处理下,氮高效品种单株不定根数、单株不定根总长、单株根干重、单株根系总吸收面积、单株根系活跃吸收面积、抽穗期冠根比多数处理有优势;增施氮肥有利于促进氮高效品种单株不定根总长和单株根活力的提高,适量施氮有利于单株不定根数、单株根干重增加,前期施氮可促进不定根的发生和伸长,后期施氮有利于不定根的充实和根系生理性状的提高。此外,增施氮肥可提高各类品种冠根比;(3)在常氮、高氮处理下,氮高效品种氮肥利用率大于氮中效、氮低效品种。(4)提高单株不定根数、单株不定根总长、单株根活力及抽穗期冠根比有利于各类品种吸氮量的提高,增加根干重对氮高效品种吸氮量的提高也有显著的促进作用。结合相关分析与通径分析结果,抽穗期冠根比及单株不定根数、单株根活力、单株不定根总长、单株根干重是影响氮高效品种吸氮能力的主要根系性状。     

Alcoholism and substance abuse among selected southern cheyenne Indians

This family and small community-based study reports the occurrence of alcoholism and co-occurring substance abuse in Southern Cheyenne Indians living in western Oklahoma. Sociocultural factors complicate operationalization of clinical data into standard (DSM-III-R) psychiatric disorder terminology; understanding sociocultural factors is essential for assessing the high rate of addictive disorders in this group. To obtain reliable and valid clinical diagnoses, data from several sources were utilized within a blind rating system: 1) SADS-L, a clinician-administered research diagnostic instrument; 2) MAST; 3) relatives; 4) medical records; 5) other official documents. The sample consisted of 69 males (45 alcoholics) and 97 females (36 alcoholics). Among clinically significant substance abusers (moderate impairment of function), 22 of 24 were alcoholics. In non-alcoholics, mean MAST scores were 8.8 (males) and 5.1 (females); in alcoholics, 32.0 (males) and 38.7 (females). Mean age of onset on heavy use of alcohol was 20.1 yrs. (males) and 22.8 (females) (p = 0.047); among all alcoholics, 86% (males) and 64% (females) had early onset (< 25 yrs. old). When data from 98 unrelated subjects were analyzed separately, similar findings were observed except that mean age of onset of heavy use of alcohol was more discrepant between males and females, viz. 20.1 versus 22.8 yrs. (p = 0.02). Among those with substance abuse disorders, early age of onset was present in all but one female. In these Cheyenne, alcoholism is usually clinically severe and early in onset; it often co-occurs with substance abuse, also early in onset.