1,494 research outputs found
Consumer Preferences for Fruit and Vegetables with Credence-Based Attributes: A Review
credence goods, consumer preferences and attitudes, sustainable fruit and vegetables, consumer research., Agricultural Finance, Consumer/Household Economics, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety, Institutional and Behavioral Economics, Marketing, Productivity Analysis,
Guidelines for physical weed control research: flame weeding, weed harrowing and intra-row cultivation
A prerequisite for good research is the use of appropriate methodology. In order to aggregate sound research methodology, this paper presents some tentative guidelines for physical weed control research in general, and flame weeding, weed harrowing and intra-row cultivation in particular. Issues include the adjustment and use of mechanical weeders and other equipment, the recording of impact factors that affect weeding performance, methods to assess effectiveness, the layout of treatment plots, and the conceptual models underlying the experimental designs (e.g. factorial comparison, dose response).
First of all, the research aims need to be clearly defined, an appropriate experimental design produced and statistical methods chosen accordingly. Suggestions on how to do this are given. For assessments, quantitative measures would be ideal, but as they require more resources, visual classification may in some cases be more feasible. The timing of assessment affects the results and their interpretation.
When describing the weeds and crops, one should list the crops and the most abundantly present weed species involved, giving their density and growth stages at the time of treatment. The location of the experimental field, soil type, soil moisture and amount of fertilization should be given, as well as weather conditions at the time of treatment.
The researcher should describe the weed control equipment and adjustments accurately, preferably according to the prevailing practice within the discipline. Things to record are e.g. gas pressure, burner properties, burner cover dimensions and LPG consumption in flame weeding; speed, angle of tines, number of passes and direction in weed harrowing.
The authors hope this paper will increase comparability among experiments, help less experienced scientists to prevent mistakes and essential omissions, and foster the advance of knowledge on non-chemical weed management
Biodiversity research sets sail: showcasing the diversity of marine life
The World Congress on Marine Biodiversity was held in the City of Arts and Sciences, Valencia, from 10 to 15 November 2008, showcasing research on all aspects of marine biodiversity from basic taxonomic exploration to innovative conservation strategies and methods to integrate research into environmental policy
Headache and pregnancy. a systematic review
This systematic review summarizes the existing data on headache and pregnancy with a scope on clinical headache phenotypes, treatment of headaches in pregnancy and effects of headache medications on the child during pregnancy and breastfeeding, headache related complications, and diagnostics of headache in pregnancy. Headache during pregnancy can be both primary and secondary, and in the last case can be a symptom of a life-threatening condition. The most common secondary headaches are stroke, cerebral venous thrombosis, subarachnoid hemorrhage, pituitary tumor, choriocarcinoma, eclampsia, preeclampsia, idiopathic intracranial hypertension, and reversible cerebral vasoconstriction syndrome. Migraine is a risk factor for pregnancy complications, particularly vascular events. Data regarding other primary headache conditions are still scarce. Early diagnostics of the disease manifested by headache is important for mother and fetus life. It is especially important to identify "red flag symptoms" suggesting that headache is a symptom of a serious disease. In order to exclude a secondary headache additional studies can be necessary: electroencephalography, ultrasound of the vessels of the head and neck, brain MRI and MR angiography with contrast ophthalmoscopy and lumbar puncture. During pregnancy and breastfeeding the preferred therapeutic strategy for the treatment of primary headaches should always be a non-pharmacological one. Treatment should not be postponed as an undermanaged headache can lead to stress, sleep deprivation, depression and poor nutritional intake that in turn can have negative consequences for both mother and baby. Therefore, if non-pharmacological interventions seem inadequate, a well-considered choice should be made concerning the use of medication, taking into account all the benefits and possible risks
Memory beyond memory in heart beating: an efficient way to detect pathological conditions
We study the long-range correlations of heartbeat fluctuations with the
method of diffusion entropy. We show that this method of analysis yields a
scaling parameter that apparently conflicts with the direct evaluation
of the distribution of times of sojourn in states with a given heartbeat
frequency. The strength of the memory responsible for this discrepancy is given
by a parameter , which is derived from real data. The
distribution of patients in the (, )-plane yields a neat
separation of the healthy from the congestive heart failure subjects.Comment: submitted to Physical Review Letters, 5 figure
Male and female sex hormones in primary headaches
Background: The three primary headaches, tension-type headache, migraine and cluster headache, occur in both genders, but all seem to have a sex-specific prevalence. These gender differences suggest that both male and female sex hormones could have an influence on the course of primary headaches. This review aims to summarise the most relevant and recent literature on this topic. Methods: Two independent reviewers searched PUBMED in a systematic manner. Search strings were composed using the terms LH, FSH, progesteron, estrogen, DHEA, prolactin, testosterone, androgen, headach, migrain, "tension type" or cluster. A timeframe was set limiting the search to articles published in the last 20 years, after January 1st 1997. Results: Migraine tends to follow a classic temporal pattern throughout a woman's life corresponding to the fluctuation of estrogen in the different reproductive stages. The estrogen withdrawal hypothesis forms the basis for most of the assumptions made on this behalf. The role of other hormones as well as the importance of sex hormones in other primary headaches is far less studied. Conclusion: The available literature mainly covers the role of sex hormones in migraine in women. Detailed studies especially in the elderly of both sexes and in cluster headache and tension-type headache are warranted to fully elucidate the role of these hormones in all primary headaches
A field vegetable transplanter for use in both tilled and no-till soils
A commercial, manually fed vegetable transplanter was modified and adapted to work in no-till soils. Details
of the modifications are described in this article. The aim of this research was to evaluate the performance of this transplanter
under actual field conditions in both tilled and no-till soils. The draft force in the no-till soil was measured for
different working tools mounted for tilling or loosening a narrow band of soil before passing with the furrower. The combination
of a ripper shank opener with a straight nose point resulted in the lowest draft force values per unit of working depth.
The transplanter accuracy and transplant success rate were evaluated in different vegetable crops. The accuracy parameters
(multiple index, miss index, quality of feed index, and precision) were estimated and in general were similar in the tilled
and no-till soils, indicating that the transplanter was able to operate in both soil conditions with the same accuracy. The
transplant success rates were also similar in both soil conditions. The transplanter thus offers a satisfactory technical solution
for transplanting vegetables in both tilled and no-till soils
Testing of Roller-Crimper-and-Undercutting-Blade-Equipped Prototype for Plants Termination
The use of roller crimpers to terminate plants and obtain a natural mulch before cash crop establishment has been identified as a valid and sustainable approach to control weeds. Several enhancements have been evaluated to improve and speed up plant termination to avoid delays in cash crop planting and consequent yield losses, which can occur with standard roller crimpers. In the present study, a new prototype machine provided with a roller crimper and an undercutting blade, allowing it to simultaneously crimp plant stems and cut root systems, has been designed, realized, and tested. The aim of the research was therefore to evaluate the effectiveness of the prototype for plant termination and to compare it with a commercial roller crimper. The termination was performed on a spontaneous vegetation cover (weeds). A monophasic exponential decay model to evaluate the weed termination rate over time was performed. The fitted model showed that the prototype is able to achieve a greater and faster weed devitalization compared to the commercial roller crimper, with a lower plateau (0.23 vs. 5.35 % of greenness of plant material, respectively) and higher constant of decay (1.45 vs. 0.39 day−1, respectively). Further studies are needed to evaluate the prototype’s effectiveness in relation to different soil textures, moisture conditions, and amounts of plant biomass to manage, to further improve the machine and extend its use in a broad range of situations, including cover crop termination
Combining roller crimpers and flaming for the termination of cover crops in herbicide-free no-till cropping systems
The termination of cover crops in conventional no-till systems is mostly conducted mechanically
in combination with herbicides. Combining flaming and roller crimpers could be a viable
solution to avoid using herbicides for cover crop termination in farming systems where herbicides
are banned, or at least to reduce their use in an integrated management approach.
This research tested the effects of flaming used in combination with three different types of
roller crimpers to terminate a fall-sown cover crop mixture of winter pea and barley. The
cover crop termination rate was visually assessed in terms of percentage of green cover
provided by cover crop plants at different intervals from the termination date, and estimated
using a log-logistic non-linear regression model with four parameters. Machine performance
data are also reported. The results show that, irrespective of the roller type, flaming significantly
boosted the effect of the roller crimpers. In fact, an economic threshold for cover crop
suppression of 85% was reached only when the rollers were used in combination with flaming.
Nevertheless, none of the methods were able to reach the 100% of cover crop suppression.
In some case, the combined use of flaming and roller crimpers allowed reaching the
90% of cover crop devitalisation, which happened six weeks after the termination date.
More importantly, the use of flaming in combination with rollers shortened the time needed
to achieve the estimated levels of devitalisation, compared with the rollers used alone. We
conclude that flaming is an effective tool to increase the effectiveness of roller crimpers.
Nevertheless, further research is needed to identify solutions to overcome the barrier of the
high operational costs of flaming, which is constraining its wider adoption by farmers. Future
studies could focus, for instance, on the development of a new prototype of combined
machine for crimping and flaming the cover crops simultaneously, which could potentially
reduce the operational costs
Innovative living mulch management strategies for organic conservation field vegetables: evaluation of continuous mowing, flaming, and tillage performances
Organic vegetable production is particularly affected by weed pressure and mechanical
weeding is the major tactic implemented by growers to keep weeds under economic thresholds. Living
mulch (LM) has been shown to provide several environmental services; however, LM management
is required to avoid competition between service crops and cash crops. The aim of this trial was
to evaluate two innovative LM-based management systems: a system that provided LM growth
regulation by means of flaming (LM-FL) and a system where the LM was regularly mowed by an
autonomous mower (LM-AM), both compared with a control without LM and based on standard
tillage operations (TILL). The three management systems were evaluated in terms of crop production,
weed control, and energy consumption on a 2 yr organic crop rotation of cauliflower (Brassica oleracea L.
var botrytis) and eggplant (Solanum melongena L.). LM-AM produced an acceptable fresh marketable
yield for both vegetable crops. Moreover, the weed dry biomass obtained in LM-AM-managed
plots was lower compared to the LM-FL plots and ranged approximately from 200 to 300 kg ha1.
Furthermore, LM-AM management resulted in lower energy consumption (2330 kWh ha1 with
respect to the TILL system and 7225 kWh ha1 with respect to the LM-FL system). The results of
this trial suggest that autonomous mowers have a great potential to improve LM management and
help with implementing sustainable organic vegetable systems
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